US11543497B2 - Sensor chip, electronic equipment, and apparatus - Google Patents

Abstract

[Problem]

The present disclosure proposes a technology that makes it possible to further reduce the influence of an error arising from a resolution of processing relating to measurement of the distance.

[Solving Means]

A sensor chip is provided which includes a light reception section configured to receive light projected from a light source and reflected by an imaging target to detect, for each given detection period, a reception light amount of the reflected light within the given period, a measurement section configured to measure a distance to the imaging object based on the reception light amount, and a control section configured to apply at least one of a first delay amount or a second delay amount, whose resolutions relating to control are different from each other, to control of a first timing at which the light reception section is to detect the reception light amount thereby to control a relative time difference between the first timing and a second timing at which the light source is to project light with a resolution finer than the resolutions of the first delay amount and the second delay amount in response to the first delay amount and the second delay amount.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. § 371 as a U.S. National Stage Entry of International Application No. PCT/JP2018/033860, filed in the Japanese Patent Office as a Receiving Office on Sep. 12, 2018, which claims priority to Japanese Patent Application Number JP2017-245944, filed in the Japanese Patent Office on Dec. 22, 2017, each of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to a sensor chip, electronic equipment, and an apparatus.

BACKGROUND ART

In recent years, in a sensor chip of a CMOS (Complementary Metal Oxide Semiconductor) image sensor, a ToF (Time of Flight) sensor, a fluorescence detection sensor or the like, it is demanded to perform control at a high speed. For example, in a sensor chip for which such high speed driving as exceeds a modulation frequency of 1 MHz is demanded, it is necessary to control pulses of a control signal on the order of sub microseconds or 10 nanoseconds.

For example,PTL 1 discloses a ToF sensor that outputs measurement information at random such that signal processing for tracking an object measured in a three-dimensional image can be carried out immediately.

CITATION LISTPatent Literature

[PTL 1]

Japanese Patent Laid-Open No. 2012-049547

SUMMARYTechnical Problem

Incidentally, in the case where the ToF sensor described above is utilized to perform distance measurement, operation relating to projection of light to an object that becomes a target of light measurement (imaging object) and operation relating to detection of the light reflected by the object are sometimes synchronized with each other. In such a case as just described, upon measurement of the distance, an error arising from a resolution in processing relating to the synchronization reveals as an error of a distance measurement result and, after all, sometimes has an influence on the accuracy of the measurement.

Therefore, the present disclosure proposes a technology that makes it possible to further reduce the influence of an error arising from a resolution of processing relating to measurement of the distance.

Solution to Problem

According to the present disclosure, there is provided a sensor chip including a light reception section configured to receive light projected from a light source and reflected by an imaging target to detect, for each given detection period, a reception light amount of the reflected light within the given period, a measurement section configured to measure a distance to the imaging object based on the reception light amount, and a control section configured to apply at least one of a first delay amount or a second delay amount, whose resolutions relating to control are different from each other, to control of a first timing at which the light reception section is to detect the reception light amount thereby to control a relative time difference between the first timing and a second timing at which the light source is to project light with a resolution finer than the resolutions of the first delay amount and the second delay amount in response to the first delay amount and the second delay amount

According to the present disclosure, there is provided electronic equipment including a light source, a light reception section configured to receive light projected from the light source and reflected by an imaging target to detect, for each given detection period, a reception light amount of the reflected light within the given period, a measurement section configured to measure a distance to the imaging object based on the reception light amount, and a control section configured to apply each of a first delay amount and a second delay amount, whose resolutions relating to control are different from each other, to control of one of a first timing at which the light reception section is to detect the reception light amount and a second timing at which the light source is to project light thereby to control a relative time difference between the first timing and the second timing with a resolution finer than the resolutions of the first delay amount and the second delay amount.

According to the present disclosure, there is provided an apparatus including a light source, a light reception section configured to receive light projected from the light source and reflected by an imaging target to detect, for each given detection period, a reception light amount of the reflected light within the given period, a measurement section configured to measure a distance to the imaging object based on the reception light amount, and a control section configured to apply each of a first delay amount and a second delay amount, whose resolutions relating to control are different from each other, to control of one of a first timing at which the light reception section is to detect the reception light amount and a second timing at which the light source is to project light thereby to control a relative time difference between the first timing and the second timing with a resolution finer than the resolutions of the first delay amount and the second delay amount.

Advantageous Effect of Invention

As described above, according to the present disclosure, a technology that can further reduce the influence of an error arising from a resolution of processing relating to measurement of the distance.

It is to be noted that the advantageous effect described above is not necessarily restrictive, and some advantageous effects indicated in the present specification or other advantageous effects that can be recognized from the present specification may be applicable together with the advantageous effect described above or in place of the advantageous effect described above.

BRIEF DESCRIPTION OF DRAWINGS

FIG.1 is a block diagram depicting a configuration example of a first embodiment of a sensor chip to which the present technology is applied.

FIG.2 is a view depicting a configuration example of a global controlling circuit.

FIG.3 is a view depicting a configuration of a rolling controlling circuit.

FIG.4 is a block diagram depicting a first modification of a sensor chip ofFIG.1.

FIG.5 is a block diagram depicting a second modification of the sensor chip ofFIG.1.

FIG.6 is a block diagram depicting a configuration example of a second embodiment of the sensor chip.

FIG.7 is a perspective view depicting a configuration example of a third embodiment of the sensor chip.

FIG.8 is a block diagram depicting the configuration example of the third embodiment of the sensor chip.

FIG.9 is a block diagram depicting a first modification of the sensor chip ofFIG.8.

FIG.10 is a block diagram depicting a second modification of the sensor chip ofFIG.8.

FIG.11 is a block diagram depicting a configuration example of a fourth embodiment of the sensor chip.

FIG.12 is a block diagram depicting a configuration example of a fifth embodiment of the sensor chip.

FIG.13 is a perspective view depicting a configuration example of a sixth embodiment of the sensor chip.

FIG.14 is a block diagram depicting the configuration example of the sixth embodiment of the sensor chip.

FIG.15 is a block diagram depicting a first modification of the sensor chip ofFIG.14.

FIG.16 is a block diagram depicting a second modification of the sensor chip ofFIG.14.

FIG.17 is a block diagram depicting a third modification of the sensor chip ofFIG.14.

FIG.18 is a block diagram depicting a fourth modification of the sensor chip ofFIG.14.

FIG.19 is a block diagram depicting a fifth modification of the sensor chip ofFIG.14.

FIG.20 is a block diagram depicting a sixth modification of the sensor chip ofFIG.14.

FIG.21 is a block diagram depicting a seventh modification of the sensor chip ofFIG.14.

FIG.22 is a block diagram depicting an eighth modification of the sensor chip ofFIG.14.

FIG.23 is a perspective view depicting a configuration example of a seventh embodiment of the sensor chip.

FIG.24 is a perspective view depicting a first modification of the sensor chip ofFIG.23.

FIG.25 is a perspective view depicting a second modification of the sensor chip ofFIG.23.

FIG.26 is a block diagram depicting a configuration example of an eight embodiment of the sensor chip and a modification of the same.

FIG.27 is a block diagram depicting a configuration example of an imaging apparatus.

FIG.28 is an explanatory view illustrating an overview of a principle of distance measurement by the indirect ToF.

FIG.29 is an explanatory view illustrating an example of operation control of a distance image sensor according to a comparative example.

FIG.30 is an explanatory view illustrating a basic idea of control of a distance image sensor according to an embodiment of the present disclosure.

FIG.31 is an explanatory view illustrating a first control example of the distance image sensor according to the embodiment.

FIG.32 is an explanatory view illustrating the first control example of the distance image sensor according to the embodiment.

FIG.33 is an explanatory view illustrating a second control example of the distance image sensor according to the embodiment.

FIG.34 is an explanatory view illustrating the second control example of the distance image sensor according to the embodiment.

FIG.35 is a view depicting an example of a schematic configuration of a variable delay circuit that can be applied to the distance image sensor according to the embodiment.

FIG.36 is a view depicting another example of a schematic configuration of the variable delay circuit that can be applied to the distance image sensor according to the embodiment.

FIG.37 is a view depicting a further example of a schematic configuration of the variable delay circuit that can be applied to the distance image sensor according to the embodiment.

FIG.38 is a view depicting a still further example of a schematic configuration of the variable delay circuit that can be applied to the distance image sensor according to the embodiment.

FIG.39 is a functional block diagram depicting a first configuration example of the distance image sensor according to the embodiment.

FIG.40 is a functional block diagram depicting a second configuration example of the distance image sensor according to the embodiment.

FIG.41 is a functional block diagram depicting a third configuration example of the distance image sensor according to the embodiment.

FIG.42 is a view depicting an example of usage in which an image sensor is used.

FIG.43 is a view depicting an example of a schematic configuration of an endoscopic surgery system.

FIG.44 is a block diagram depicting an example of a functional configuration of a camera head and a CCU.

FIG.45 is a block diagram depicting an example of schematic configuration of a vehicle control system.

FIG.46 is a diagram of assistance in explaining an example of installation positions of an outside-vehicle information detecting section and an imaging section.

DESCRIPTION OF EMBODIMENTS

In the following, a preferred embodiment of the present disclosure is described in detail with reference to the accompanying drawings. It is to be noted that, in the present specification and drawings, components having substantially same functional configurations are denoted by like reference characters and overlapping description of them is omitted.

It is to be noted that the description is given in the following order.

1. Configuration Example

2. Overview of ToF

3. Technical Feature

4. Usage Example and Application Example

5. Conclusion

<<1. Configuration Example>>

First, an example of a configuration of a sensor chip applied to a distance image sensor according to an embodiment of the present disclosure and an example of a configuration of the distance image sensor are described.

<First Configuration Example of Sensor Chip>

FIG.1 is a block diagram depicting a configuration example of a first embodiment of a sensor chip to which the present technology is applied.

As depicted inFIG.1, thesensor chip11 is configured including apixel array section12, a globalcontrolling circuit13, a rolling controllingcircuit14, a column ADC (Analog-to-Digital Converter)15 and an inputting and outputtingsection16, which are disposed on a semiconductor substrate.

Thepixel array section12 is a rectangular region in which various sensor elements according to functions of thesensor chip11, for example, photoelectric conversion elements that perform photoelectric conversion of light, are disposed in an array. In the example depicted inFIG.1, thepixel array section12 is a horizontally elongated rectangular region having a long side extending in the horizontal direction and a short side extending in the vertical direction.

The globalcontrolling circuit13 is a control circuit that outputs a global controlling signal for controlling the plurality of sensor elements disposed in thepixel array section12 such that they are driven all at once (simultaneously) at a substantially same timing. In the configuration example ofFIG.1, the globalcontrolling circuit13 is disposed on the upper side of thepixel array section12 such that the longitudinal direction thereof extends along a long side of thepixel array section12. Accordingly, in thesensor chip11, acontrol line21 for supplying the global controlling signal outputted from the globalcontrolling circuit13 to the sensor elements of thepixel array section12 is disposed in the upward and downward direction of thepixel array section12 for each column of the sensor elements disposed in a matrix in thepixel array section12.

The rolling controllingcircuit14 is a control circuit that outputs rolling controlling signals for controlling the plurality of sensor elements disposed in thepixel array section12 such that the sensor elements are successively (sequentially) driven in order for each row. In the configuration example depicted inFIG.1, the rolling controllingcircuit14 is disposed on the right side of thepixel array section12 such that the longitudinal direction thereof extends along a short side of thepixel array section12.

Thecolumn ADC15 converts analog sensor signals outputted from the sensor elements of thepixel array section12 to digital values with AD (Analog-to-Digital)) in parallel for the individual columns. At this time, thecolumn ADC15 can remove reset noise included in the sensor signals, for example, by performing a CDS (Correlated Double Sampling: correlated double sampling) process for the sensor signals.

The inputting and outputtingsection16 has provided thereon terminals for performing inputting and outputting between thesensor chip11 and an external circuit, and for example, power necessary for driving the globalcontrolling circuit13 is inputted to thesensor chip11, for example, through the inputting and outputtingsection16. In the configuration example depicted inFIG.1, the inputting and outputtingsection16 is disposed along the globalcontrolling circuit13 such that it is positioned adjacent the globalcontrolling circuit13. For example, since the globalcontrolling circuit13 has high power consumption, in order to reduce the influence of an IR drop (voltage drop), preferably the inputting and outputtingsection16 is disposed in the proximity of the globalcontrolling circuit13.

Thesensor chip11 is configured in this manner, and a layout in which the globalcontrolling circuit13 is disposed so as to extend along a long side of thepixel array section12 is adopted. Consequently, the distance from the globalcontrolling circuit13 to a sensor element disposed at the remote end of the control line21 (the lower end in the example ofFIG.1) can be made shorter than that in an alternative layout in which the globalcontrolling circuit13 is disposed so as to extend along a short side of thepixel array section12.

Accordingly, since thesensor chip11 can improve the delay amount and the slew rate that occur with a global controlling signal outputted from the globalcontrolling circuit13, it can perform control for the sensor elements at a high speed. Especially, in the case where thesensor chip11 is an image sensor that performs global shutter driving, high speed control of a transfer signal or a reset signal to be supplied to the pixels, an overflow gate signal and so forth becomes possible. On the other hand, in the case where thesensor chip11 is a ToF sensor, high speed control of a MIX signal becomes possible.

For example, in a ToF sensor, a fluorescence detection sensor or the like, if the slew rate of a global controlling signal or the delay amount of a global controlling signal, which occurs in accordance with the distance from a driving element, or the like differs for each sensor element, then this gives rise to a detection error. In contrast, since thesensor chip11 can improve the delay amount and the slew rage that occur in the global controlling signal as described above, such a detection error as described above can be suppressed.

Further, in the case where thesensor chip11 is a ToF sensor, a fluorescence detection sensor or the like, not only such a number of times of on/off control as may exceed 100 times is required for an exposure period but also the current consumption increases because the toggle frequency is high. In contrast, in thesensor chip11, the inputting and outputtingsection16 can be disposed in the proximity of the globalcontrolling circuit13 as described above such that an independent wiring line can be provided for the power supply.

Further, while, in thesensor chip11, the globalcontrolling circuit13 frequently operates during an exposure period, the rolling controllingcircuit14 remains stopping. On the other hand, in thesensor chip11, while the rolling controllingcircuit14 operates within a reading out period, the globalcontrolling circuit13 frequently is stopping. Therefore, in thesensor chip11, it is demanded to control the globalcontrolling circuit13 and the rolling controllingcircuit14 independently of each other. Further, in thesensor chip11, in order to secure in-plane synchronization, it is general to adopt such a clock tree structure depicted inFIG.2C as hereinafter described, preferably the globalcontrolling circuit13 is disposed independently of the rolling controllingcircuit14.

Accordingly, in the case where higher speed control is demanded as in thesensor chip11, better control can be anticipated by adopting the layout in which the globalcontrolling circuit13 and the rolling controllingcircuit14 are individually and independently of each other. It is to be noted, if the globalcontrolling circuit13 and the rolling controllingcircuit14 are disposed individually and independently of each other, then any one of a layout in which they extend along a same direction and another layout in which they extend orthogonally to each other may be adopted.

It is to be noted that, although, in the description of the present embodiment, it is described that the upper side in each figure is the upper side of thepixel array section12 and the lower side in each figure is the lower side of thepixel array section12 in accordance with the configuration example depicted, if, for example, the globalcontrolling circuit13 is disposed so as to extend along a long side of thepixel array section12, then similar working effects can be achieved on whichever one of the upper side and the lower side the globalcontrolling circuit13 is disposed. Further, this similarly applies also to thepixel array section12 and thecolumn ADC15.

A configuration of the globalcontrolling circuit13 is described with reference toFIG.2.

FIG.2A depicts a first configuration example of the globalcontrolling circuit13;FIG.2B depicts a second configuration example of the globalcontrolling circuit13; andFIG.2C depicts a third configuration example of the globalcontrolling circuit13. It is to be noted that, although the globalcontrolling circuit13 is configured such that it simultaneously outputs global controlling signals in accordance with the number of columns of sensor elements disposed in thepixel array section12, inFIG.2, as part of the configuration, a configuration that outputs eight global controlling signals at the same time is schematically depicted.

The globalcontrolling circuit13 depicted inFIG.2A is configured including oneinternal buffer31 and eight drivingelements32ato32h.

As depicted inFIG.2A, the globalcontrolling circuit13 has such a connection configuration that theinternal buffer31 is connected to one end of an internal wiring line provided along the longitudinal direction and the drivingelements32ato32hare connected to the internal wiring line toward one direction according to the positions of the control lines21. Accordingly, a global controlling signal inputted to the globalcontrolling circuit13 is supplied from one end side of the internal wiring line (in the example ofFIG.2, the left side) to the drivingelements32ato32hthrough theinternal buffer31 and is simultaneously outputted to thecontrol lines21 individually connected to the drivingelements32ato32h.

The globalcontrolling circuit13A depicted inFIG.2B is configured including twointernal buffers31aand31band eight drivingelements32ato32h.

As depicted inFIG.2B, the globalcontrolling circuit13A has such a connection configuration that theinternal buffers31aand31bare connected to the opposite ends of an internal wiring line provided along the longitudinal direction of the globalcontrolling circuit13A and the drivingelements32ato32hare connected to the internal wiring line toward one direction according to the positions of thecontrol lines21 ofFIG.1. Accordingly, a global controlling signal inputted to the globalcontrolling circuit13A is supplied from the opposite ends of the internal wiring line through theinternal buffers31aand31bto the drivingelements32ato32hand is simultaneously outputted to thecontrol lines21 individually connected to the drivingelements32ato32h.

The globalcontrolling circuit13B depicted inFIG.2C is configured including seveninternal buffers31ato31gand eight drivingelements32ato32h.

As depicted inFIG.2C, the globalcontrolling circuit13B has such a connection configuration that a clock tree structure is configured from theinternal buffers31ato31gand, in the final stage, it is connected to the drivingelements32ato32hdisposed along one direction according to the positions of the control lines21. For example, the clock tree structure is such a structure that a structure that, in the first stage, an output of oneinternal buffer31 is inputted to twointernal buffers31 and, in the second state, inputs of the twointernal buffers31 are inputted to fourinternal buffers31 is repeated in a plurality of stages. Accordingly, a global controlling signal inputted to the globalcontrolling circuit13B is supplied to the drivingelements32ato32hthrough the clock tree structure configured from theinternal buffers31ato31gand is simultaneously outputted to thecontrol lines21 connected to the drivingelements32ato32h.

The globalcontrolling circuit13B having such a configuration as described above can avoid occurrence of a delay between the drivingelements32ato32hand can ensure in-plane uniformity, for example, in comparison with the globalcontrolling circuits13 and13A. In other words, it is preferable to adopt the globalcontrolling circuit13B in an application in which synchronization is requested strongly over a direction in which thedriving elements32 are lined up.

A configuration of the rolling controllingcircuit14 is described with reference toFIG.3.

FIG.3A depicts a first configuration example of the rolling controllingcircuit14, andFIG.3B depicts a second configuration example of the rolling controllingcircuit14. It is to be noted that, although the rolling controllingcircuit14 is configured such that it sequentially outputs rolling controlling signals according to the row number of the sensor elements disposed in thepixel array section12, inFIG.3, as part of the configuration, a configuration that outputs eight rolling controlling signals sequentially is schematically depicted.

The rolling controllingcircuit14 depicted inFIG.3A adopts a shift register system and is configured including twointernal buffers41 and42, eightregisters43ato43hand eight drivingelements44ato44h. It is to be noted that, although the configuration example in which twointernal buffers41 and42 are disposed is depicted for simplification, a configuration may otherwise be adopted in which a plurality of internal buffers are disposed according to wiring line lengths of the internal buffers.

As depicted inFIG.3A, the rolling controllingcircuit14 has such a connection configuration that theinternal buffer41 is connected to one end of an internal wiring line provided along the longitudinal direction and theregisters43ato43hare connected to the internal wiring line according to the positions of the rows of the sensor elements disposed in thepixel array section12. Further, the rolling controllingcircuit14 has such a connection configuration that theinternal buffer42 is connected to theregister43aand theregisters43ato43hare connected sequentially and besides the drivingelements44ato44hare connected to theregisters43ato43h, respectively.

Accordingly, in the rolling controllingcircuit14, a start pulse supplied to theregister43athrough theinternal buffer42 is sequentially shifted to theregisters43ato43hin accordance with a clock supplied through theinternal buffer41 and is sequentially outputted as rolling controlling signals from the drivingelements44ato44hconnected to theregisters43ato43h, respectively.

The rollingcontrolling circuit14A depicted inFIG.3B adopts a decoder system and is configured including twointernal buffers41 and42, adecoder45, eight ANDgates46ato46hand eight drivingelements44ato44h. It is to be noted that, for thedecoder45, any one of a decoder of a type that includes a latch and a decoder of another type that does not include a latch may be used. For example, in the case where thedecoder45 is of the type that latches a signal, a system by which addresses are sent at once, another system by which addresses are sent divisionally or the like can be adopted.

As depicted inFIG.3B, in the rollingcontrolling circuit14A, theinternal buffer41 is connected to thedecoder45, and theinternal buffer42 is connected to an input terminal of the ANDgates46ato46hand thedecoder45 is connected to an input terminal of the ANDgates46ato46hfor each row. Further, the rollingcontrolling circuit14A has a connection configuration in which output terminals of the ANDgates46ato46hare connected to the drivingelements44ato44h, respectively.

Accordingly, in the rollingcontrolling circuit14A, a pulse supplied to the ANDgates46ato46hthrough theinternal buffer42 is sequentially outputted as rolling controlling signals from the drivingelements44ato44hof rows designated by addresses supplied to thedecoder45 through theinternal buffer41.

As described with reference toFIGS.2 and3, the globalcontrolling circuit13 and the rolling controllingcircuit14 have circuit configurations different from each other.

FIG.4 is a block diagram depicting a first modification of thesensor chip11 depicted inFIG.1. It is to be noted that, from among blocks configuring the sensor chip11-adepicted inFIG.4, components common to those of thesensor chip11 ofFIG.1 are denoted by like reference characters, and detailed description of them is omitted.

In particular, as depicted inFIG.4, the sensor chip11-ahas a configuration common to thesensor chip11 ofFIG.1 in terms of the disposition of thepixel array section12, rolling controllingcircuit14,column ADC15 and inputting and outputtingsection16.

Meanwhile, the sensor chip11-ahas a configuration different from that of thesensor chip11 ofFIG.11 in that two global controlling circuits13-1 and13-2 are disposed so as to extend along the upper side and the lower side of thepixel array section12, respectively, and the driving elements32-1 and32-2 are connected to the opposite ends of thecontrol line21. In particular, the sensor chip11-ais configured such that the driving element32-1 included in the global controlling circuit13-1 supplies a global controlling signal from the upper end of thecontrol line21 and the driving element32-2 included in the global controlling circuit13-2 supplies a global controlling signal from the lower end of thecontrol line21.

The sensor chip11-aconfigured in this manner can suppress a skew between the two driving element32-1 and driving element32-2 and can eliminate a dispersion in delay time that occurs in global controlling signals propagated along thecontrol line21. Consequently, in the sensor chip11-a, control for the sensor elements can be performed at a higher speed. It is to be noted that, in the sensor chip11-a, it is necessary to perform the control such that the delay difference in outputting of global controlling signals is avoided from becoming great such that through current may not be generated.

FIG.5 is a block diagram depicting a second modification of thesensor chip11 depicted inFIG.1. It is to be noted that, from among blocks configuring the sensor chip11-bdepicted inFIG.5, components common to those of thesensor chip11 ofFIG.1 are denoted by like reference characters, and detailed description of them is omitted.

In particular, as depicted inFIG.5, the sensor chip11-bis configured commonly to thesensor chip11 ofFIG.1 in terms of the disposition of the sensor chip11-b,pixel array section12, rolling controllingcircuit14,column ADC15 and inputting and outputtingsection16.

On the other hand, the sensor chip11-bhas a different configuration from that of thesensor chip11 ofFIG.1 in that the two global controlling circuits13-1 and13-2 are disposed so as to extend along the upper side and the lower side of thepixel array section12, respectively, and the two control lines21-1 and21-2 are disposed such that they are separate at the center of a column of the sensor elements disposed in a matrix in thepixel array section12. Further, in the sensor chip11-b, the driving element32-1 is connected to an upper end of the control line21-1, and the driving element32-2 is connected to a lower end of the control line21-2.

Accordingly, the sensor chip11-bis configured such that, to the sensor elements disposed on the upper side with respect to the center of thepixel array section12, the driving element32-1 included in the global controlling circuit13-1 supplies a global controlling signal from the upper end of the control line21-1. Further, the sensor chip11-bis configured such that, to the sensor elements disposed on the lower side with respect to the center of thepixel array section12, the driving element32-2 included in the global controlling circuit13-2 supplies a global controlling signal from the lower end of the control line21-2.

According to the sensor chip11-bconfigured in this manner, the distance from the driving element32-1 to a sensor element disposed at the remote end (in the example ofFIG.5, the lower end) of the control line21-1 and the distance from the driving element32-2 to a sensor element disposed at the remote end (in the example ofFIG.5, the upper end) of the control line21-2 can made shorter, for example, than that in thesensor chip11 ofFIG.1. Consequently, the sensor chip11-bcan perform control for the sensor elements at a further higher speed because the delay amount and the slew rate occurring with global controlling signals outputted from the global controlling circuits13-1 and13-2 can be further reduced.

<Second Configuration Example of Sensor Chip>

A second embodiment of a sensor chip to which the present technology is applied is described with reference toFIG.6. It is to be noted that, from among blocks configuring thesensor chip11A depicted inFIG.6, components common to those of thesensor chip11 ofFIG.1 are denoted by like reference characters, and detailed description of them is omitted.

As depicted inFIG.6, thesensor chip11A is configured such that apixel array section12A, a globalcontrolling circuit13A, a rollingcontrolling circuit14A, acolumn ADC15A and an inputting andoutputting section16A are disposed on a semiconductor substrate.

Thesensor chip11A is different in configuration from thesensor chip11 ofFIG.1 in that thepixel array section12A is a vertically elongated rectangular area in which the longer sides are provided to extend in the vertical direction and the shorter sides are provided to extend in the horizontal direction. Accordingly, in thesensor chip11A, the globalcontrolling circuit13A and the inputting andoutputting section16A are disposed on the left side of thepixel array section12A so as to extend along a long side of thepixel array section12A. With this, acontrol line21A is disposed, for each row of the sensor elements disposed in a matrix in thepixel array section12A, toward the leftward and rightward direction of thepixel array section12A.

Further, in thesensor chip11A, the rollingcontrolling circuit14A is disposed on the right side of thepixel array section12A (on the side opposing to the globalcontrolling circuit13A) so as to extend along a long side of thepixel array section12A. It is to be noted that, although the globalcontrolling circuit13A and thepixel array section12A may be disposed on the same side with respect to thepixel array section12A, in this case, since it is supposed that the wiring line length of any one of them becomes longer, it is preferable to adopt such arrangement as depicted inFIG.6.

Further, in thesensor chip11A, thecolumn ADC15A is disposed on the lower side of thepixel array section12A so as to extend along a short side of thepixel array section12A. The reason why thecolumn ADC15A is disposed in a direction orthogonal to the rollingcontrolling circuit14A in this manner is that it is necessary to turn on the sensor elements connected to one AD converter one by one, and such a layout that individual wiring lines overlap with each other is avoided.

According to thesensor chip11A configured in this manner, the wiring line length of thecontrol line21A can be reduced by the layout in which the globalcontrolling circuit13A is disposed so as to extend along a long side of thepixel array section12A similarly to thesensor chip11 ofFIG.1. Accordingly, thesensor chip11A can perform control for the sensor elements at a higher speed similarly to thesensor chip11 ofFIG.1.

<Third Configuration Example of Sensor Chip>

A third embodiment of a sensor chip to which the present technology is applied is described with reference toFIGS.7 to10. It is to be noted that, from among blocks configuring thesensor chip11B depicted inFIGS.7 to10, components common to those of thesensor chip11 ofFIG.1 are denoted by like reference characters, and detailed description of them is omitted.

FIG.7 depicts a perspective view of thesensor chip11B, andFIG.8 depicts a block diagram of thesensor chip11B.

As depicted inFIG.7, thesensor chip11B has a stacked structure in which asensor substrate51 on which apixel array section12 is formed and alogic substrate52 on which a globalcontrolling circuit13 is formed are stacked. Further, thesensor chip11B has such a connection structure that, in a peripheral region of thesensor chip11B in which it does not overlap with thepixel array section12 as viewed in plan,control lines21 of thesensor substrate51 and the globalcontrolling circuit13 of thelogic substrate52 are connected to each other. In particular, in the example depicted inFIG.7, in thesensor chip11B, a plurality ofcontrol lines21 disposed along a column direction of the sensor elements disposed in a matrix in thepixel array section12 are connected to the globalcontrolling circuit13 side on the upper side of thesensor substrate51.

Accordingly, in thesensor chip11B, a global controlling signal outputted from the globalcontrolling circuit13 is supplied to the sensor elements of thepixel array section12 from the upper side of thesensor substrate51 as indicated by a void arrow mark inFIG.7. At this time, the globalcontrolling circuit13 is configured such that it is disposed such that the longitudinal direction thereof extends along a long side of thepixel array section12 and thesensor chip11B has the shortest distance from the globalcontrolling circuit13B to the sensor elements of thepixel array section12.

A configuration of thesensor chip11B is described further with reference toFIG.8.

Thesensor substrate51 has apixel array section12 and TSV (Through Silicon Via) regions53-1 to53-3 disposed thereon. Thelogic substrate52 has a globalcontrolling circuit13, a rolling controllingcircuit14, acolumn ADC15, alogic circuit17 and TSV regions54-1 to54-3 disposed thereon. For example, in thesensor chip11B, a sensor signal outputted from each sensor element of thepixel array section12 is AD converted by thecolumn ADC15 and is subjected to various signal processes by thelogic circuit17, whereafter it is outputted to the outside.

The TSV regions53-1 to53-3 and the TSV regions54-1 to54-3 are regions in which through-electrodes for electrically connecting thesensor substrate51 and thelogic substrate52 to each other are formed, and a through electrode is disposed for eachcontrol line21. Accordingly, the TSV regions53-1 to53-3 and the TSV regions54-1 to54-3 are disposed such that they overlap with each other when thesensor substrate51 and thelogic substrate52 are stacked. It is to be noted that not only through electrodes can be used for connection in theTSV regions54, but also, for example, micro bump or copper (Cu—Cu) connection can be utilized.

According to thesensor chip11B configured in this manner, the wiring line length of thecontrol line21 can be made short by the layout in which the globalcontrolling circuit13 is disposed so as to extend along a long side of thepixel array section12 similarly to thesensor chip11 ofFIG.1. Accordingly, thesensor chip11B can perform control for the sensor elements at a higher speed similarly to thesensor chip11 ofFIG.1.

FIG.9 is a block diagram depicting a first modification of thesensor chip11B depicted inFIG.8. It is to be noted that, from among blocks configuring thesensor chip11B-a depicted inFIG.9, components common to those of thesensor chip11B ofFIG.8 are denoted by like reference characters, and detailed description of them is omitted.

As depicted inFIG.9, in particular, thesensor chip11B-a is configured commonly to thesensor chip11B ofFIG.8 in that it has such a stacked structure that thesensor substrate51 on which thepixel array section12 is formed and thelogic substrate52 on which the globalcontrolling circuit13 is formed are stacked.

On the other hand, thesensor chip11B-a is different in configuration from thesensor chip11B ofFIG.8 in that the two global controlling circuits13-1 and13-2 are disposed on thelogic substrate52 so as to extend along the upper side and the lower side of thepixel array section12, respectively, and two control lines21-1 and21-2 are disposed such that they are separate from each other at the center of the columns of the sensor elements disposed in a matrix on thepixel array section12.

In particular, in thesensor chip11B-a, the driving element32-1 is connected to an upper end of the control line21-1 and the driving element32-2 is connected to the lower end of the control line21-2 similarly as in the sensor chip11-bdepicted inFIG.5. Accordingly, thesensor chip11B-a is configured such that, to the sensor elements disposed on the upper side with respect to the center of thepixel array section12, the driving element32-1 included in the global controlling circuit13-1 supplies a global controlling signal from the upper end of the control line21-1. Further, thesensor chip11B-a is configured such that, to the sensor elements disposed on the lower side with respect to the center of thepixel array section12, the driving element32-2 included in the global controlling circuit13-2 supplies a global controlling signal from the lower end of the control line21-2.

In thesensor chip11B-a configured in such a manner as described above, the distance from the driving element32-1 to a sensor element disposed at the remote end (in the example ofFIG.9, at the lower end) of the control line21-1 and the distance from the driving element32-2 to a sensor element disposed at the remote end (in the example ofFIG.9, at the upper end) of the control line21-2 can be made shorter, for example, than that in thesensor chip11B ofFIG.8. Consequently, thesensor chip11B-a can perform control for the sensor elements at a higher speed because the delay amount and the slew rate occurring with global signals outputted from the global controlling circuits13-1 and13-2 can be further reduced.

FIG.10 is a block diagram depicting a second modification of thesensor chip11B depicted inFIG.8. It is to be noted that, from among blocks configuring thesensor chip11B-b depicted inFIG.10, components common to those of thesensor chip11B ofFIG.8 are denoted by like reference characters, and detailed description of them is omitted.

In particular, as depicted inFIG.10, thesensor chip11B-b is common in configuration to thesensor chip11B ofFIG.8 in that it has a stacked structure in which asensor substrate51 on which apixel array section12 is formed and alogic substrate52 on which a globalcontrolling circuit13 is formed are stacked.

On the other hand, thesensor chip11B-b is different in configuration from thesensor chip11B ofFIG.8 in that two global controlling circuits13-1 and13-2 are disposed on thelogic substrate52 so as to extend along the upper side and the lower side of thepixel array section12, respectively, and driving elements32-1 and32-2 are connected to the opposite ends of acontrol line21.

In particular, in thesensor chip11B-b, the driving element32-1 included in the global controlling circuit13-1 supplies a global controlling signal from the upper end of thecontrol line21 and the driving element32-2 included in the global controlling circuit13-2 supplies a global controlling signal from the lower end of thecontrol line21 similarly to the sensor chip11-adepicted inFIG.4.

Thesensor chip11B-b configured in this manner can suppress a skew between the two driving element32-1 and driving element32-2 and can eliminate a dispersion in delay time that occurs in a global controlling signal propagated along thecontrol line21. Consequently, in thesensor chip11B-b, control for the sensor elements can be performed at a higher speed. It is to be noted that, in thesensor chip11B-b, it is necessary to perform the control such that the delay difference in outputting of global controlling signals is avoided from becoming great such that through current may not be generated.

In thesensor chip11B configured in such a manner as described above, control for the sensor elements in the stacked structure in which thesensor substrate51 and thelogic substrate52 are stacked can be performed at a higher speed similarly as in thesensor chip11 ofFIG.1.

It is to be noted that, in the configuration examples depicted inFIGS.8 to10, thecolumn ADC15 is configured such that sensor signal is read out from the lower end side of thepixel array section12 through the TSV region53-3 and the TSV region54-3 disposed on the lower side. In addition to such a configuration as just described, for example, twocolumn ADCs15 are disposed in the proximity of the upper and lower sides and configured such that a sensor signal is read out from the upper end side and the lower end side of thepixel array section12 by the twocolumn ADCs15.

<Fourth Configuration Example of Sensor Chip>

A fourth embodiment of a sensor chip to which the present technology is applied is described with reference toFIG.11. It is to be noted that, from among blocks configuring thesensor chip11C depicted inFIG.11, components common to those of thesensor chip11B ofFIG.8 are denoted by like reference characters, and detailed description of them is omitted.

In particular, as depicted inFIG.11, thesensor chip11C is common in configuration to thesensor chip11B ofFIG.8 in that it has a stacked structure in which asensor substrate51 on which apixel array section12 is formed and alogic substrate52 on which a globalcontrolling circuit13 is formed are stacked.

On the other hand, thesensor chip11C is different in configuration from thesensor chip11B ofFIG.8 in that a pixel array section12C has a vertically elongated rectangular region similarly to thepixel array section12A of thesensor chip11A depicted inFIG.6. Accordingly, in thesensor chip11C, the global controlling circuit13C is disposed on the left side of thelogic substrate52 so as to extend along a long side of the pixel array section12C. With this, acontrol line21C is disposed toward the leftward and rightward direction of the pixel array section12C for each row of the sensor elements disposed in a matrix in the pixel array section12C.

Further, in thesensor chip11C, a rollingcontrolling circuit14C is disposed on the right side of the logic substrate52 (side opposing to the global controlling circuit13C) so as to extend along a long side of the pixel array section12C. It is to be noted that, although the global controlling circuit13C and the pixel array section12C may be disposed on the same side with respect to thelogic substrate52, in this case, since it is supposed that the wiring line length of any one of them becomes longer, it is preferable to adopt such arrangement as depicted inFIG.11.

Furthermore, in thesensor chip11C, the column ADC15C is disposed on the lower side of thelogic substrate52 so as to extend along a short side of the pixel array section12C. The reason why the column ADC15C is disposed in a direction orthogonal to the rollingcontrolling circuit14C in this manner is that it is necessary to turn on the sensor elements connected to one AD converter one by one, and such a layout that individual wiring lines overlap with each other is avoided.

According to thesensor chip11C configured in this manner, the wiring line length of thecontrol line21C can be reduced by the layout in which the global controlling circuit13C is disposed so as to extend along a long side of the pixel array section12C similarly to thesensor chip11B ofFIG.8. Accordingly, thesensor chip11C can perform control for the sensor elements at a higher speed similarly to thesensor chip11B ofFIG.8.

<Fifth Configuration Example of Sensor Chip>

A fifth embodiment of a sensor chip to which the present technology is applied is described with reference toFIG.12. It is to be noted that, from among blocks configuring the sensor chip11D depicted inFIG.12, components common to those of thesensor chip11B ofFIG.8 are denoted by like reference characters, and detailed description of them is omitted.

In particular, as depicted inFIG.12, the sensor chip11D is common in configuration to thesensor chip11B ofFIG.8 in that it has a stacked structure in which asensor substrate51 on which apixel array section12 is formed and alogic substrate52 on which a globalcontrolling circuit13 is formed are stacked.

On the other hand, the sensor chip11D is different in configuration from thesensor chip11B ofFIG.8 in that, a plurality ofcolumn ADCs15, in the example ofFIG.12, ADCs15-1 to15-12, are disposed corresponding to a region of thesensor substrate51, in which thepixel array section12 is formed, are disposed on thelogic substrate52.

For example, the sensor chip11D is configured such that anADC15 is disposed for each predetermined region of thepixel array section12. In the case where the12 ADCs15-1 to15-12 are used as depicted inFIG.12, anADC15 is disposed for each of 12 divisional regions into which thepixel array section12 is divided equally, and AD conversion of sensor signals outputted from the sensor elements provided in the individual regions is performed in parallel. It is to be noted that, in addition to the configuration in which anADC15 is disposed for each of predetermined regions of thepixel array section12, for example, a configuration in which oneADC15 is disposed for each of sensor elements included in thepixel array section12 may be applied.

According to the sensor chip11D configured in this manner, the wiring line length of thecontrol line21 can be made short by the layout in which the globalcontrolling circuit13 is disposed so as to extend along a long side of thepixel array section12 similarly to thesensor chip11B ofFIG.8. Accordingly, the sensor chip11D can perform control for the sensor elements at a higher speed similarly to thesensor chip11B ofFIG.8.

Further, in the sensor chip11D, restriction of the positional relationship between the rolling controllingcircuit14 and thecolumn ADC15 to such constraints to thecolumn ADC15 depicted inFIG.8 is eliminated. For example, although, in the sensor chip11D depicted inFIG.12, the rolling controllingcircuit14 is disposed on the right side of thelogic substrate52, the rolling controllingcircuit14 may be disposed on any of the upper side and the lower side. In other words, the rolling controllingcircuit14 may be disposed at any place if there is no restriction in regard to the location of thepixel array section12 with respect to the sensor chip11D (for example, the center position of the sensor chip11D with respect to the optical center).

As an alternative, for example, in the case where there is a strong restriction to the optical center and the center position of the sensor chip11D, the layout can be balanced well by disposing the rolling controllingcircuit14 at a position on the opposite side to the region in which thecolumn ADC15 is disposed with respect to the globalcontrolling circuit13. This makes it possible to improve the characteristic of the sensor chip11D.

<Sixth Configuration Example of Sensor Chip>

A sixth embodiment of a sensor chip to which the present technology is applied is described with reference toFIGS.13 to22. It is to be noted that, from among blocks configuring thesensor chip11E depicted inFIGS.13 to22, components common to those of thesensor chip11B ofFIGS.7 and8 are denoted by like reference characters, and detailed description of them is omitted.

As depicted inFIG.13, thesensor chip11E has a stacked structure in which asensor substrate51 on which apixel array section12 is formed and alogic substrate52 on which a globalcontrolling circuit13 is formed are stacked similarly to thesensor chip11B depicted inFIG.7. Further, thesensor chip11E has such a connection structure that the globalcontrolling circuit13 is disposed such that it overlaps with the center of thepixel array section12 when thesensor chip11E is viewed in plan and the globalcontrolling circuit13 is connected to thecontrol line21 at the central portion of thepixel array section12.

For example, in the case where thesensor chip11E is connectable at thepixel array section12 by interconnection of copper (Cu) configuring wiring lines, connection utilizing micro bumps or TSVs or like connection, the distance from the drivingelement32 to a sensor element disposed at the remote end of thecontrol line21 can be made short.

A configuration of thesensor chip11E is further described with reference toFIG.14.

As depicted inFIG.14, in thesensor substrate51, thepixel array section12 is a horizontally elongated rectangular region having long sides extending in the horizontal direction and short sides extending in the vertical direction. Accordingly, on thelogic substrate52, the globalcontrolling circuit13 is disposed such that the longitudinal direction thereof extends along a long side of thepixel array section12. Further, the globalcontrolling circuit13 is disposed substantially at the center of thelogic substrate52 such that a wiring line for outputting from the drivingelement32 of the globalcontrolling circuit13 is connected to the center of acontrol line21 disposed toward the upward and downward direction of thepixel array section12. It is to be noted that such a configuration may be used that a wiring line for outputting from the drivingelement32 extends through the substrate from the globalcontrolling circuit13 directly toward thepixel array section12.

In thesensor chip11E configured in this manner, the distances from the drivingelement32 to sensor elements at the opposite ends of thecontrol line21 can be made short. Accordingly, since the delay amount and the slew rate of a global controlling signal can be improved, thesensor chip11E can perform control for the sensor elements at a higher speed.

Further, such a configuration as indicated by thesensor chip11E is preferable for application, for example, to a ToF sensor.

FIG.15 is a block diagram depicting a first modification of thesensor chip11E depicted inFIG.14. It is to be noted that, from among blocks configuring thesensor chip11E-a depicted inFIG.15, components common to those of thesensor chip11E ofFIG.14 are denoted by like reference characters, and detailed description of them is omitted.

In particular, as depicted inFIG.15, thesensor chip11E-a is common in configuration to thesensor chip11E ofFIG.14 in that it has a stacked structure in which asensor substrate51 on which apixel array section12 is formed and alogic substrate52 on which a globalcontrolling circuit13 is formed are stacked.

On the other hand, on thesensor substrate51, thesensor chip11E-a is different in configuration from thesensor chip11E ofFIG.14 in that two control lines21-1 and21-2 divided at the center are disposed for one row of sensor elements disposed in a matrix in thepixel array section12. Further, thesensor chip11E-a is different in configuration from thesensor chip11E ofFIG.14 in that the globalcontrolling circuit13 on thelogic substrate52 includes two driving elements32-1 and32-2 for one row of the sensor elements.

Further, thesensor chip11E-a has such a connection structure that the driving element32-1 is connected to a center side end portion of the control line21-1 and the driving element32-2 is connected to a center side end portion of the control line21-2. In particular, thesensor chip11E-a is configured such that, from among a plurality of sensor elements disposed on one row of thepixel array section12, the sensor elements disposed on the upper side with respect to the center are driven by the driving element32-1 through the control line21-1, and the sensor elements disposed on the lower side with respect to the center are driven by the driving element32-2 through the control line21-2.

According to thesensor chip11E-a configured in this manner, the distance from the driving element32-1 to a sensor element disposed at the remote end of the control line21-1 and the distance from the driving element32-2 to a sensor element disposed at the remote end of the control line21-2 can be made short similarly to thesensor chip11E ofFIG.14. Accordingly, thesensor chip11E-a can improve the delay amount and the slew rate of a global controlling signal similarly to thesensor chip11E ofFIG.14.

Further, in thesensor chip11E-a, since the load per one drivingelement32 can be reduced, the size of the drivingelement32 can be reduced from that of thesensor chip11E ofFIG.14. Furthermore, where thesensor chip11E-a is configured such that two drivingelements32 are disposed for one column of sensor elements, the layout of the drivingelements32 is integrated to one place, and the overall layout structure can be simplified.

FIG.16 is a block diagram depicting a second modification of thesensor chip11E depicted inFIG.14. It is to be noted that, from among blocks configuring thesensor chip11E-b depicted inFIG.16, components common to those of thesensor chip11E ofFIG.14 are denoted by like reference characters, and detailed description of them is omitted.

In particular, thesensor chip11E-b depicted inFIG.16 is common in configuration to thesensor chip11E ofFIG.14 in that it has a stacked structure in which asensor substrate51 on which apixel array section12 is formed and alogic substrate52 on which a globalcontrolling circuit13 is formed are stacked.

On the other hand, thesensor chip11E-b is different in configuration from thesensor chip11E ofFIG.14 in that, on thesensor substrate51, two control lines21-1 and21-2 separate at the center are disposed for one row of sensor elements disposed in a matrix in thepixel array section12. Further, thesensor chip11E-b is different in configuration from thesensor chip11E ofFIG.14 in that, on thelogic substrate52, two global controlling circuits13-1 and13-2 are disposed.

Further, thesensor chip11E-b has such a connection structure that the driving element32-1 is connected to the center of the control line21-1 and the driving element32-2 is connected to the center of the control line21-2. In particular, thesensor chip11E-b is configured such that, from among a plurality of sensor elements disposed in one row of thepixel array section12, the sensor elements disposed on the upper side with respect to the center are driven by the driving element32-1 through the control line21-1 and the sensor elements disposed on the lower side with respect to the center are driven by the driving element32-2 through the control line21-2.

In thesensor chip11E-b configured in this manner, the distance from the driving element32-1 to a sensor element disposed at the remote end of the control line21-1 and the distance from the driving element32-2 to a sensor element disposed at the remote end of the control line21-2 can be made shorter in comparison with thesensor chip11E ofFIG.14. Consequently, thesensor chip11E-b can achieve driving at a higher speed than thesensor chip11E ofFIG.14 and can achieve further improvement of the delay amount and the slew rate of a global controlling signal.

Further, as depicted inFIG.16, in thesensor chip11E-b, since the global controlling circuits13-1 and13-2 can be disposed divisionally, thelogic circuit17 can be disposed at a central location between them. It is to be noted that, though not depicted, thecolumn ADC15 may be disposed at a central location between the global controlling circuits13-1 and13-2.

Further, such a configuration as indicated by thesensor chip11E-b is suitable for application, for example, to a ToF sensor.

FIG.17 is a block diagram depicting a third modification of thesensor chip11E depicted inFIG.14. It is to be noted that, from among blocks configuring thesensor chip11E-c depicted inFIG.17, components common to those of thesensor chip11E ofFIG.14 are denoted by like reference characters, and detailed description of them is omitted.

In particular, thesensor chip11E-c depicted inFIG.17 is common in configuration to thesensor chip11E ofFIG.14 in that it has a stacked structure in which asensor substrate51 on which apixel array section12 is formed and alogic substrate52 on which a globalcontrolling circuit13 is formed are stacked.

On the other hand, thesensor chip11E-c is different in configuration from thesensor chip11E ofFIG.14 in that, on thesensor substrate51, two control lines21-1 and21-2 divided at the center are disposed for one row of sensor elements disposed in a matrix in thepixel array section12. Further, thesensor chip11E-c is different in configuration from thesensor chip11E ofFIG.14 in that two global controlling circuits13-1 and13-2 are disposed on thelogic substrate52.

Further, thesensor chip11E-c has such a connection structure that the driving element32-1 is connected to the center of the control line21-1 and the driving element32-2 is connected to the center of the control line21-2 similarly to thesensor chip11E-b ofFIG.16. Accordingly, thesensor chip11E-c can achieve driving at a higher speed than thesensor chip11E ofFIG.14 and can achieve further improvement of the delay amount and the slew rate of a global controlling signal in comparison with thesensor chip11E ofFIG.14 similarly to thesensor chip11E-b ofFIG.16.

Further, in thesensor chip11E-c, the column ADC15-1 is disposed on the upper side of thelogic substrate52 and the column ADC15-2 is disposed on the lower side of thelogic substrate52. In thesensor chip11E-c configured in this manner, since it has a structure in which the layout thereof is symmetrical upwardly and downwardly, it is improved in symmetry, and consequently, thesensor chip11E-c can be improved in characteristic.

FIG.18 is a block diagram depicting a fourth modification of thesensor block11E depicted inFIG.14. It is to be noted that, from among blocks configuring thesensor chip11E-d depicted inFIG.18, components common to those of thesensor chip11E ofFIG.14 are denoted by like reference characters, and detailed description of them is omitted.

In particular, thesensor chip11E-d depicted inFIG.18 is common in configuration to thesensor chip11E ofFIG.14 in that it has a stacked structure in which asensor substrate51 on which apixel array section12 is formed and alogic substrate52 on which a globalcontrolling circuit13 is formed are stacked.

On the other hand, thesensor chip11E-d is different in configuration from thesensor chip11E ofFIG.14 in that, on thelogic substrate52, two global controlling circuits13-1 and13-2 are disposed and that thesensor chip11E-d has such a connection structure that the global controlling circuit13-1 is connected to a substantially center of an upper half of thecontrol line21 and the global controlling circuit13-2 is connected to a substantially center of a lower half of thecontrol line21. In other words, thesensor chip11E-d is configured such that it uses asingle control line21 to which the control lines21-1 and21-2 ofFIG.17 are connected.

Thesensor chip11E-d configured in this manner can suppress a skew between the two driving element32-1 and driving element32-2 and can eliminate a dispersion in delay time that occurs in a global controlling signal propagated along thecontrol line21. Consequently, in thesensor chip11E-d, control for the sensor elements can be performed at a higher speed. It is to be noted that, in thesensor chip11E-d, it is necessary to perform the control such that the delay difference in outputting of global controlling signals is avoided from becoming great such that through current may not be generated.

FIG.19 is a block diagram depicting a fifth modification of thesensor block11E depicted inFIG.14. It is to be noted that, from among blocks configuring thesensor chip11E-e depicted inFIG.19, components common to those of thesensor chip11E ofFIG.14 are denoted by like reference characters, and detailed description of them is omitted. Further, in thesensor chip11E-e depicted inFIG.19, in order to avoid the illustration from becoming complicated, illustration of part of blocks configuring thesensor chip11E-e is omitted.

In particular, thesensor chip11E-e depicted inFIG.19 is common in configuration to thesensor chip11E ofFIG.14 in that it has a stacked structure in which asensor substrate51 on which apixel array section12 is formed and alogic substrate52 on which a globalcontrolling circuit13 is formed are stacked.

On the other hand, thesensor chip11E-e is different in configuration from thesensor chip11E ofFIG.14 in that, on thesensor substrate51, four divisional control lines21-1 to21-4 are disposed for one row of sensor elements disposed in a matrix in thepixel array section12. Further, thesensor chip11E-e is different in configuration from thesensor chip11E ofFIG.14 in that, on thelogic substrate52, four global controlling circuits13-1 to13-4 are disposed.

Further, thesensor chip11E-e has such a connection configuration that driving elements32-1 to32-4 of the global controlling circuits13-1 to13-4 are connected to central points of the control lines21-1 to21-4, respectively. Accordingly, in thesensor chip11E-e, the distance from the driving elements32-1 to32-4 to sensor elements disposed at the remote end of the respective control lines21-1 to21-4 can be further reduced. Consequently, thesensor chip11E-e can achieve further increase in speed of control for the sensor elements. It is to be noted that, although it is supposed that thecolumn ADC15A,logic circuit17 and so forth are disposed separately, also in such a case as just described, it is necessary to adopt a layout in which this does not have an influence on a characteristic.

It is to be noted that, although the configuration example depicted inFIG.19 is described using the four divisional control lines21-1 to21-4, thecontrol line21 may otherwise be divided into three control lines or five or more control lines. Thus, such a configuration can be taken that, to substantially central portions of thedivisional control lines21, respectively corresponding globalcontrolling circuits13 are connected.

FIG.20 is a block diagram depicting a sixth modification of thesensor block11E depicted inFIG.14. It is to be noted that, from among blocks configuring thesensor chip11E-f depicted inFIG.20, components common to those of thesensor chip11E ofFIG.14 are denoted by like reference characters, and detailed description of them is omitted.

In particular, thesensor chip11E-f depicted inFIG.20 is common in configuration to thesensor chip11E ofFIG.14 in that it has a stacked structure in which asensor substrate51 on which apixel array section12 is formed and alogic substrate52 on which a globalcontrolling circuit13 is formed are stacked.

On the other hand, thesensor chip11E-f is different in configuration from thesensor chip11E ofFIG.14 in that four global controlling circuits13-1 to13-4 are disposed on thelogic substrate52 and global controlling circuits13-1 to13-4 are connected at equal distances to thecontrol line21. In other words, thesensor chip11E-d is configured such that it uses asingle control line21 to which the control lines21-1 to21-4 ofFIG.19 are connected.

Thesensor chip11E-f configured in this manner can suppress a skew among the four driving elements32-1 to32-4 and can eliminate a dispersion in delay time that occurs in a global controlling signal propagated along thecontrol line21. Consequently, in thesensor chip11E-f, control for the sensor elements can be performed at a higher speed. It is to be noted that, in thesensor chip11E-f, it is necessary to perform the control such that the delay difference in outputting of global controlling signals becomes great such that through current may not be generated.

FIG.21 is a block diagram depicting a seventh modification of thesensor block11E depicted inFIG.14. It is to be noted that, from among blocks configuring thesensor chip11E-g depicted inFIG.21, components common to those of thesensor chip11E-e ofFIG.19 are denoted by like reference characters, and detailed description of them is omitted.

In particular, thesensor chip11E-g is configured including a singleglobal controlling circuit13 and is configured including buffer circuits55-1 to55-3 in place of the global controlling circuits13-2 to13-4 of thesensor chip11E-e ofFIG.19. The buffer circuits55-1 to55-3 have buffers56-1 to56-3, respectively, and an output of the drivingelement32 of the globalcontrolling circuit13 is branched by the buffers56-1 to56-3 and connected to four divisional control lines21-1 to21-4.

Also with thesensor chip11E-g configured in this manner, further increase in speed of control for the sensor elements can be achieved similarly with thesensor chip11E-e ofFIG.19.

FIG.22 is a block diagram depicting an eighth modification of thesensor block11E depicted inFIG.14. It is to be noted that, from among blocks configuring thesensor chip11E-h depicted inFIG.22, components common to those of thesensor chip11E-f ofFIG.20 are denoted by like reference characters, and detailed description of them is omitted.

In particular, thesensor chip11E-g is configured including a singleglobal controlling circuit13 and is configured including buffer circuits55-1 to55-3 in place of the global controlling circuits13-2 to13-4 of thesensor chip11E-f ofFIG.20. The buffer circuits55-1 to55-3 have buffers56-1 to56-3, respectively, and an output of the drivingelement32 of the globalcontrolling circuit13 is branched by the buffers56-1 to56-3 and connected to acontrol line21.

Also with thesensor chip11E-h configured in this manner, further increase in speed of control for the sensor elements can be achieved similarly with thesensor chip11E-f ofFIG.20.

<Seventh Configuration Example of Sensor Chip>

A seventh embodiment of a sensor chip to which the present technology is applied is described with reference toFIGS.23 to25. It is to be noted that, from among blocks configuring thesensor chip11F depicted inFIGS.23 to25, components common to those of thesensor chip11E ofFIG.13 are denoted by like reference characters, and detailed description of them is omitted.

In particular, thesensor chip11F depicted inFIG.23 has a stacked structure in which asensor substrate51 and two logic substrates52-1 and52-2 are stacked. In other words, the present technology can be applied to a structure in which three semiconductor substrates are stacked.

As depicted inFIG.23, thesensor chip11F is configured such that apixel array section12 is formed on asensor substrate51 of the first layer and a globalcontrolling circuit13 and memories61-1 and61-2 are formed on a logic substrate52-1 of the second layer while, for example, acolumn ADC15, alogic circuit17 and forth not depicted are formed on a logic substrate52-2 of the third layer.

Also in thesensor chip11F configured in this manner, by disposing the globalcontrolling circuit13 on the logic substrate52-1 along the longitudinal direction of thepixel array section12 of thesensor substrate51, control for the sensor elements can be performed at a higher speed similarly as in thesensor chip11E ofFIG.13.

Further, in thesensor chip11F in which thesensor substrate51, logic substrate52-1 and logic substrate52-2 are slacked in this order, preferably the globalcontrolling circuit13 is disposed at the center of the logic substrate52-1 stacked between thesensor substrate51 and the logic substrate52-2. Consequently, the distance from the globalcontrolling circuit13 to a sensor element disposed at the remote end of the logic substrate52-1 can be made short. Naturally, if the distance from the globalcontrolling circuit13 to a sensor element disposed at the remote end of thecontrol line21 can be made short, then the layout is not limited to such a layout as depicted inFIG.23.

FIG.24 is a perspective view depicting a first modification of thesensor chip11F depicted inFIG.23.

As depicted inFIG.24, thesensor chip11F-a is configured such that thepixel array section12 is formed on thesensor substrate51 of the first layer; the memories61-1 and61-2 are formed on the logic substrate52-1 of the second layer; and, for example, the globalcontrolling circuit13, thecolumn ADC15 andlogic circuit17 not depicted and so forth are formed on the logic substrate52-2 of the third layer.

Also in thesensor chip11F-a configured in this manner, by disposing the globalcontrolling circuit13 on the logic substrate52-2 so as to extend along the longitudinal direction of thepixel array section12 of thesensor substrate51, control for the sensor elements can be performed at a higher speed similarly as in thesensor chip11E ofFIG.13.

FIG.25 is a perspective view depicting a second modification of thesensor chip11F depicted inFIG.23.

As depicted inFIG.25, thesensor chip11F-b is configured such that thepixel array section12 is formed on thesensor substrate51 of the first layer; thememory61 is formed on the logic substrate52-1 of the second layer; and, for example, the globalcontrolling circuit13, thecolumn ADC15 andlogic circuit17 not depicted and so forth are formed on the logic substrate52-2 of the third layer. It is to be noted that thesensor chip11F-b has such a connection configuration that thecontrol line21 is connected to the globalcontrolling circuit13 utilizing a TSV region formed in a peripheral region of thesensor chip11F-b, for example, similarly to thesensor chip11B ofFIG.8.

Also in thesensor chip11F-b configured in this manner, by disposing the globalcontrolling circuit13 on the logic substrate52-2 so as to extend along the longitudinal direction of thepixel array section12 of thesensor substrate51, control for the sensor elements can be performed at a higher speed similarly as in thesensor chip11E ofFIG.13.

It is to be noted that, for example, three or more semiconductor substrates may be stacked, and a globalcontrolling circuit13 may be disposed at two locations as described hereinabove with reference toFIG.16 or a globalcontrolling circuit13 may be disposed at a plurality of locations equal to or greater than two locations. In this case, a semiconductor substrate on which thememory61 is disposed, the location or divisional number of thememory61 can be laid out suitably in response to the disposition of the globalcontrolling circuit13.

For example, such a configuration may be adopted that thepixel array section12 is disposed on a semiconductor substrate of the first layer; thecolumn ADC15,logic circuit17 and so forth are disposed on a semiconductor substrate of the second layer; and thememory61 is disposed on a semiconductor substrate of the third layer. Also in such a configuration as just described, by disposing the globalcontrolling circuit13 on the semiconductor substrate of the second layer, the wiring line length can be made short. However, the globalcontrolling circuit13 may otherwise be disposed on a semiconductor substrate on which thememory61 is disposed.

<Eighth Configuration Example of Sensor Chip>

An eighth embodiment of a sensor chip to which the present technology is applied is described with reference toFIG.26. It is to be noted that, from among blocks configuring thesensor chip11G depicted inFIG.26, components common to those of thesensor chip11E ofFIG.14 are denoted by like reference characters, and detailed description of them is omitted.

In particular, the disposition of the globalcontrolling circuit13 in thesensor chip11 is not limited to those in the embodiments described hereinabove, and such various layouts as depicted inFIG.26 can be adopted. Naturally, in any disposition, such a layout that is not depicted may be adopted if the globalcontrolling circuit13 is disposed so as to extend along a long side of thepixel array section12.

As depicted inFIG.26A, asensor chip11G has such a layout that thepixel array section12 and the globalcontrolling circuit13 are disposed on thesensor substrate51 and the rolling controllingcircuit14,column ADC15 andlogic circuit17 are disposed on thelogic substrate52. Further, in thesensor chip11G, the globalcontrolling circuit13 is disposed on the lower side of thepixel array section12 so as to extend along a long side of thepixel array section12.

As depicted inFIG.26B, asensor chip11G-a has such a layout that thepixel array section12 and the globalcontrolling circuit13 are disposed on thesensor substrate51 and the rolling controllingcircuit14,column ADC15 andlogic circuit17 are disposed on thelogic substrate52. Further, in thesensor chip11G-a, the globalcontrolling circuit13 is disposed on the upper side of thepixel array section12 so as to extend along a long side of thepixel array section12.

As depicted inFIG.26C, asensor chip11G-b has such a layout that thepixel array section12 and the global controlling circuits13-1 and13-2 are disposed on thesensor substrate51 and the rolling controllingcircuit14,column ADC15 andlogic circuit17 are disposed on thelogic substrate52. Further, in thesensor chip11G-b, the global controlling circuits13-1 and13-2 are disposed on the upper side and the lower side of thepixel array section12 so as to extend along a long side of thepixel array section12, respectively.

As depicted inFIG.26D, asensor chip11G-c has such a layout that thepixel array section12 and the global controlling circuits13-1 and13-2 are disposed on thesensor substrate51 and the rolling controllingcircuit14,column ADC15 andlogic circuit17 are disposed on thelogic substrate52. Further, in thesensor chip11G-c, the global controlling circuits13-1 and13-2 are disposed on the upper side and the lower side of thepixel array section12 so as to extend along a long side of thepixel array section12, respectively, and the two control lines21-1 and21-2 are disposed such that they are separate at the center of a column of the sensor elements disposed in a matrix on thepixel array section12.

As depicted inFIG.26E, asensor chip11G-d has such a layout that thepixel array section12 and the global controlling circuits13-1 and13-2 are disposed on thesensor substrate51 and the rolling controllingcircuit14,column ADC15 andlogic circuit17 are disposed on thelogic substrate52. Further, in thesensor chip11G-d, the inputting and outputtingsection16 is disposed on thelogic substrate52 so as to extend along a long side of thepixel array section12.

For example, thesensor chip11G-d is configured such that it supplies power from the inputting and outputtingsection16 to the globalcontrolling circuit13 through the TSV region54-1 and the TSV region53-1. It is to be noted that, in addition to utilization of a TSV, interconnection of copper (Cu) configuring wiring lines, micro bumps and so forth may be utilized to supply power to the globalcontrolling circuit13. Further, for the wiring line for supplying power to the globalcontrolling circuit13, a same connection method as that for thecontrol line21 may be used or a connection method of some other combination may be used. Further, in addition to the configuration in which semiconductor substrates of two layers are stacked, also in a configuration in which semiconductor substrates of three layers are stacked, preferably the globalcontrolling circuit13 is disposed in the proximity of the inputting and outputtingsection16 similarly.

It is to be noted that, while the various layouts depicted inFIG.26 indicate exampled in which thecolumn ADC15 is disposed on one side of thelogic substrate52, a layout in which thecolumn ADC15 is disposed on the opposite upper and lower sides of thelogic substrate52 may be adopted. Further, the position of thecolumn ADC15 or thelogic circuit17 is not restricted to such disposition as depicted inFIG.26.

As described above, by applying a stacked structure to thesensor chip11, the globalcontrolling circuit13 can be disposed in various layouts, which increases the degree of freedom in layout and increases the effect of controlling the globalcontrolling circuit13 and the rolling controllingcircuit14 individually.

<Configuration Example of Distance Image Sensor>

FIG.27 is a block diagram depicting a configuration example of a distance image sensor that is an electronic apparatus utilizing thesensor chip11.

As depicted inFIG.27, thedistance image sensor201 is configured including an optical system202, asensor chip203, animage processing circuit204, amonitor205 and amemory206. Thus, thedistance image sensor201 can acquire a distance image according to the distance of an imaging object by receiving light (modulated light or pulse light) projected from alight source apparatus211 toward the imaging object and reflected by the surface of the imaging object.

The optical system202 is configured having one or a plurality of lenses and introduces image light (incident light) from an imaging object to thesensor chip203 such that an image is formed on a light reception face (sensor section) of thesensor chip203.

As thesensor chip203, thesensor chip11 of the embodiments described hereinabove is applied, and a distance signal indicative of a distance determined from a reception signal (APD OUT) outputted from thesensor chip203 is supplied to theimage processing circuit204.

Theimage processing circuit204 performs image processing for constructing a distance image on the basis of a distance signal supplied from thesensor chip203, and a distance image (image data) obtained by the imaging processing is supplied to and displayed on themonitor205 or supplied to and stored (recorded) into thememory206.

In thedistance image sensor201 configured in this manner, by applying thesensor chip11 described above, for example, a more accurate distance image can be acquired by performance of higher speed control.

It is to be noted that thedistance image sensor201 and thelight source apparatus211 may be configured as a unitary member. In this case, a module in which thedistance image sensor201 and thelight source apparatus211 are configured integrally can correspond to an example of the electronic equipment that utilizes thesensor chip11 described above.

<<2. Overview of ToF>>

As an example of the technology capable of being applied to the distance measurement in which the distance image sensor according to the embodiment of the present disclosure is utilized, an overview of a technology called “ToF (time of flight)” is described. The ToF is a technology fir performing distance measurement by calculating a time period after light is projected from a distance image sensor until the light returns to the distance image sensor after reflected by an imaging object using some method. As the ToF, for example, a technology called direct ToF (Direct ToF) and another technology called indirect ToF (InDirect ToF) are available. It is to be noted that, in the following description, the time period after light is projected from the distance image sensor until the light returns to the distance image sensor after reflected by an imaging object is referred to sometimes as “flight time of light” or simply as “ToF” for the convenience of description.

The technology called direct ToF is a technique by which light flight time is measured directly to measure the distance to an imaging object. In particular, in the direct ToF, pulse light emitted only for a very short period of time from a light source provided on the distance image sensor (or a light source provided together with the distance image sensor) is projected to an imaging object to directly measure the time period until the light is reflected by the imaging object and received by a sensor chip provided on the distance image sensor. By multiplying one half the time period measured in this manner by the speed of light, the distance between the distance image sensor and the imaging object can be calculated. From such a characteristic as just described, the measurement accuracy by the direct ToF sometimes depends upon the resolution in time measurement by the distance image sensor.

On the other hand, the indirect ToF is a method by which the variation of a physical quantity, which depends upon the light flight time, is measured to indirectly measure the light flight time and then the distance to an imaging object is measured on the basis of a result of the measurement.

As a particular example of the indirect ToF, a method is available by which the delay of time after light is projected from the distance image sensor until it is reflected by an imaging object and returns to the distance image sensor is detected as a phase difference. For example,FIG.28 is an explanatory view illustrating an overview relating to the principle of the distance measurement by the indirect ToF. It is to be noted that adistance image sensor201 depicted inFIG.28 is a view schematically depicting thedistance image sensor201 described hereinabove with reference toFIG.27. In particular,reference numerals211 and203 depicted inFIG.28 correspond to thelight source apparatus211 and thesensor chip203 in thedistance image sensor201 depicted inFIG.27.

As depicted inFIG.28, thedistance image sensor201 causes thelight source apparatus211 to project light (modulation light or pulse light) toward an imaging object and causes thesensor chip203 to detect the light reflected by the imaging object. It is to be noted that, in the following description, while description is given focusing on a case in which pulse light is projected from thelight source apparatus211 for the convenience of description, also it is possible to replace the pulse light into modulation light.

In particular, thedistance image sensor201 projects pulse light P11 periodically from thelight source apparatus211 and controls operation of thesensor chip203 so as to be driven in synchronism with a cycle in which the pulse light P11 is projected (in other words, the shutter is released). Consequently, the sensor elements of thesensor chip203 receive pulse light P13 projected from thelight source apparatus211 and reflected by the imaging object to detect the light reception amount of the pulse light P13 in synchronism with the cycle described above (namely, accumulated charge is read out). In other words, a period within which the sensor elements of thesensor chip203 detect pulse light P13 reflected by the imaging object (hereinafter referred to also as “detection period”) is set in synchronism with the cycle described above.

On the basis of such a configuration as described above, thedistance image sensor201 causes the sensor elements of thesensor chip203 to detect the pulse light P13 reflected by the imaging object individually during detection periods for individual phases according to the cycle described above within which the pulse light P11 is projected from thelight source apparatus211. As the detection periods for the individual phases according to the cycle described above, for example, taking a predetermined phase as zero degrees, a detection period from zero degrees to 180 degrees and another detection period from 180 degrees to 360 degrees are set. Further, a further detection period from 90 degrees to 270 degrees and a still further detection period from 270 degrees to 90 degrees may be set. In particular, within each of the detection periods set for the individual phases according to the cycle described, the pulse light P13 reflected by the imaging object is detected individually.

A phase difference according to the distance between thedistance image sensor201 and the imaging object appears between the pulse light P11 (irradiation light) projected from thelight source apparatus211 toward the imaging object and the pulse light P13 (reflection light) reflected by the imaging object. At this time, the difference between charge amounts (namely, light reception amounts) accumulated during the cycle for each phase (in other words, the ratio of the charge amounts accumulated during the cycle for each phase) depends upon the phase difference between the irradiation light (pulse light P11) and the reflection light (pulse light P13) (in other words, the delay time).

In particular, in the indirect ToF, the light flight time is measured indirectly in accordance with the difference between the charge amounts accumulated individually during the detection period for each phase (namely, the ratio of the charge amounts between the phases), and the distance between the distance image sensor and the imaging object is calculated on the basis of a result of the measurement. From such a characteristic as described above, the distance measurement accuracy by the indirect ToF depends upon the cycle of pulse light projected from the light source (in other words, upon the pulse width of pulse light), and there is a tendency that basically the distance measurement accuracy increases as the cycle decreases.

Note that it is assumed that, in the following description, in order to further facilitate a feature of the distance image sensor according to the embodiment of the present disclosure, unless otherwise specified, the distance measurement is performed by the indirect ToF.

<<3. Technical Feature>>

Subsequently, a technical feature of the distance image sensor according to the embodiment of the present disclosure is described particularly focusing on control of a configuration relating to the distance measurement.

As described above, in the case where distance measurement is performed by the indirect ToF, the sensor chip for detecting pulse light (reflection light) reflected by an imaging object is driven so as to synchronize with a cycle in which the pulse light is projected from the light source apparatus. Therefore, in the case where the distance measurement is performed by the indirect ToF, control for synchronizing operation of the light source apparatus for projecting pulse light (hereinafter referred to also as “operation of the light source apparatus” simply) and operation of the sensor chip for detecting the pulse light reflected by an imaging object (hereinafter referred to also as “operation of the sensor chip” simply) with each other is sometimes performed. It is to be noted that the timing at which the light source apparatus projects pulse light corresponds to an example of the “second timing.” Further, the timing at which the sensor chip detects the pulse light reflected by the imaging object corresponds to an example of the “first timing.” In particular, the relative time difference between the first timing and the second timing is controlled by the control described above, and after all, the synchronization between the first timing and the second timing is performed.

Comparative Example

Here, in order to further facilitate a feature of the distance image sensor according to the embodiment of the present disclosure, an example of operation control of the distance image sensor according to the comparative example is described first particularly focusing on control for synchronizing operation of the light source apparatus and operation of the sensor chip with each other. For example,FIG.29 is an explanatory view illustrating an example of operation control of the distance image sensor according to the comparative example. In the example depicted inFIG.29, a driving signal for driving sensor elements of the sensor chip (hereinafter referred to also as “pixel driving signal”) is delayed to perform the synchronization between operation of the light source apparatus and operation of the sensor chip.

In particular, in the example depicted inFIG.29, the resolution in delay adjustment of the pixel driving signal is td1. In particular, in the example depicted inFIG.29, the minimum unit adjusting the delay of the pixel driving signal (LSB: Least-Significant Bit) is td1, and, in other words, the adjustment of the delay is performed in a unit of td1. It is to be noted that, in the example ofFIG.29, delay signals after delays by 1 LSB to 3 LSB are performed for the pixel driving signal are depicted together.

Further, inFIG.29, reference character T11 schematically indicates a timing at which, in the case where the light source apparatus is driven on the basis of a light source driving signal, the light source apparatus actually emits light by a delay by a driving circuit for driving the light source apparatus or the like. In particular, reference character R2 schematically indicates a delay amount of the delay by the driving circuit for driving the light source apparatus or the like. In particular, in the example depicted inFIG.29, a delay is performed in a unit of td1 for the pixel driving signal such that the sensor elements of the sensor chip perform light reception operation in synchronism with a light emission timing T11 of the light source apparatus thereby to perform synchronization between operation of the light source apparatus and operation of the sensor chip.

On the other hand, as depicted inFIG.29, in the distance image sensor according to the comparative example, it is difficult to adjust the synchronization between operation of the light source apparatus and operation of the sensor chip with a resolution finer than td1 from such a characteristic that the delay of the pixel driving signal is adjusted in a unit of td1. Therefore, in the distance image sensor according to the comparative example, an error upon synchronization between the pixel driving signal and the light source driving signal (namely, an error occurring upon synchronization between operation of the light source apparatus and operation of the sensor chip) is superposed with a phase difference between the pulse light (irradiation light) projected from the light source apparatus toward the imaging object and the pulse light (reflection light) reflected by the imaging object. There is the possibility that such an error as just described may reveal, for example, as an error of a result of the distance measurement and, in particular, there is the possibility that the error may become a factor of deterioration of the distance measurement accuracy. In other words, in the distance image sensor according to the comparative example, it is difficult to set the resolution in correction for eliminating an error, which is to be superposed on the phase difference together with the synchronization between the pixel driving signal and the light source driving signal, (such resolution is hereinafter referred to also as “phase adjustment resolution”) finer than the resolution td1 in adjustment of the delay of the pixel driving signal (hereinafter referred to also as “delay adjustment resolution td1”). Therefore, in the distance image sensor according to the comparative example, there is a case in which it is difficult to eliminate an error finer than the delay adjustment resolution td1 from among errors that are superposed on the phase difference together with the synchronization between the pixel driving signal and the light source driving signal.

As a countermeasure for solving the problem described above, a method is available by which a delay circuit having a finer resolution td1 for adjustment of the delay is applied. However, in this case, it becomes necessary to adopt a smaller element (for example, a capacitor, a resistor or the like) as a delay element to be applied to a delay circuit and, depending upon a resolution to be demanded, it is sometimes difficult to implement the method.

From such a background as described above, in order to measure the distance with higher accuracy, implementation of a mechanism is demanded, which makes it possible to correct an error, which is superposed on a phase difference between the irradiation light and the reflection light, with a higher resolution together with synchronization between operation of the light source apparatus and operation of the sensor chip. Therefore, the present disclosure proposes an example of a technology that makes it possible to further improve the phase adjustment resolution to improve the accuracy in distance measurement. More particularly, the present disclosure proposes an example of a technology that makes it possible to control the relative delay between operation of the light source and operation of the sensor chip (namely, the relative time difference between operation timings of the light source apparatus and the sensor chip) with a resolution finer than the resolution of a delay circuit itself applied to the control of the delay.

<Basic Idea>

First, an overview of a basic idea of the control of the distance image sensor according to an embodiment of the present disclosure is described with reference toFIG.30.FIG.30 is an explanatory view illustrating a basic idea of control of the distance image sensor according to the embodiment of the present disclosure.

In the distance image sensor according to the embodiment of the present disclosure, light that indicates periodic repetitions of a predetermined pattern like pulse light or modulation light is used as light to be projected to an image object, and the phase difference between the irradiation light and the reflection light is measured. Further, in the distance image sensor according to the embodiment of the present disclosure, the relative delay between operation of the light source apparatus and operation of the sensor chip is controlled to synchronize the operation of the light source apparatus and the operation of the sensor chip with each other. On the basis of such premises, the distance image sensor according to the embodiment of the present disclosure controls the relative delay between operation of the light source apparatus and operation of the sensor chip by applying individual delays by a plurality of delay circuits having resolutions (delay adjustment resolutions) different from each other to a pixel driving signal or a light source driving signal. It is to be noted that the pixel driving signal corresponds to an example of the “first driving signal,” and the light source driving signal corresponds to one example of the “second driving signal.”

For example, in the example depicted inFIG.30, the timing at which a pixel of the sensor chip is driven and the timing at which the light source is driven are adjusted (controlled) independently of each other by delaying the pixel driving signal and the light source driving signal with delay circuits having delay adjustment resolutions different from each other. In other words, in the example depicted inFIG.30, delay amounts whose delay adjustment resolutions are different from each other are applied individually to the control of the timing for driving a pixel of the sensor chip and the control of the timing for driving the light source apparatus. For example, in the example depicted inFIG.30, the resolution relating to delay adjustment of the pixel driving signal is td1 while the resolution relating to delay adjustment of the light source signal is td2. It is to be noted that details of the present control are hereinafter described in detail as “first control example.”

Meanwhile, as another example, one of the timing for driving a pixel of the sensor chip and the timing for driving the light source apparatus may be adjusted (controlled) by applying a plurality of delays by a plurality of delay circuits having delay adjustment resolutions different from each other to one of the pixel driving signal and the light source driving signal. In other words, a plurality of delay amounts having delay adjustment resolutions different from each other may be applied to one of the control of the timing for driving a pixel of the sensor chip and the control of the timing for driving the light source apparatus. It is to be noted that details of the present control are hereinafter described separately as “second control example.”

First Control Example

First, a first control example of the distance image sensor according to the embodiment of the present disclosure is described. For example,FIGS.31 and32 are explanatory views illustrating the first control example of the distance image sensor according to the embodiment of the present disclosure.

First, an overview of delay control according to the present control example is described with reference toFIG.31. In the present control example, a plurality of driving signals different from each other are individually delayed by delay circuits having delay adjustment resolutions different from each other to control the relative delay amount between the plurality of driving signals. For example, inFIG.31, input signals I₁₁and I₁₂correspond individually to driving signals before the phase difference between them is adjusted, and output signals O₁₁and O₁₂individually correspond to driving signals after the phase difference between the input signals I₁₁and I₁₂is adjusted.Reference numeral1010 corresponds to a configuration (hereinafter referred to also as “phase adjustment circuit”) that delays a plurality of driving signals inputted thereto to control the relative control amount between the plurality of driving signals.

Thephase adjustment circuit1010 includes a firstvariable delay circuit1011 and a secondvariable delay circuit1013 that have delay adjustment resolutions different from each other. It is to be noted that the delay adjustment resolution of the firstvariable delay circuit1011 is represented by td1 and the delay adjustment resolution of the secondvariable delay circuit1013 is represented by td2. On the basis of such a configuration as just described, the firstvariable delay circuit1011 performs a delay for the input signal I₁₁and outputs the delayed input signal I₁₁as the output signal O₁₁. At this time, the delay amount of the delay performed for the input signal I₁₁by the firstvariable delay circuit1011 is controlled in a unit of td1 on the basis of a delay controlling signal D₁₁. Meanwhile, the secondvariable delay circuit1013 performs a delay for the input signal I₁₂and outputs the delayed input signal I₁₂as the output signal O₁₂. At this time, the delay amount of the delay performed for the input signal I₁₂is controlled in a unit of td2 on the basis of a delay controlling signal D₁₂. It is to be noted that one of the input signals I₁₁and I₁₂corresponds to the light source driving signal before the delay is performed therefor, and the other can correspond to the pixel driving signal before the delay is performed therefor.

Referring toFIG.31, reference character R11 schematically denotes a delay amount of a relative delay between the input signals I₁₁and I₁₂. Meanwhile, reference character R13 schematically denotes a delay amount of a relative delay between the output signals O₁₁and O₁₂. As can be recognized from the comparison between the delay amounts R11 and R13, where thephase adjustment circuit1010 performs a delay for a plurality of driving signals (for example, the input signals I₁₁and I₁₂) inputted thereto, the relative delay amount between driving signals to be outputted from the phase adjustment circuit1010 (namely, between the output signals O₁₁and O₁₂). In particular, the difference between the delay amount applied to the input signal I₁₁in a unit of td1 by the firstvariable delay circuit1011 and the delay amount applied to the input signal I₁₂in a unit of td2 by the secondvariable delay circuit1013 becomes the adjustment amount of the relative delay between the input signals I₁₁and I₁₂(hereinafter referred to also as “phase adjustment amount”).

Here, the phase adjustment amount between the input signals I₁₁and I₁₂in the case where a delay is performed for each of the input signals I₁₁and I₁₂in the example depicted inFIG.31 is described taking a particular example with reference toFIG.32. In the example depicted inFIG.32, the input signals I₁₁and I₁₂and delay signals after a delay is performed for the input signals I₁₁and I₁₂(namely, the output signals O₁₁and O₁₂) are depicted. It is to be noted that, in the example depicted inFIG.32, as the delay signals individually corresponding to the input signals I₁₁and I₁₂, delay signals where a delay of delay amounts 1 LSB to 3 LSB is performed by delay circuits corresponding to the input signals (namely, the input signals I₁₁and I₁₂) are depicted.

Referring toFIG.32, reference character R21 schematically denotes a delay amount (in other words, a phase adjustment amount) of the relative delay between a delay signal where a delay of a delay amount of 1 LSB is performed for the input signal I₁₁and a delay signal where a delay of a delay amount of 1 LSB is performed for the input signal I₁₂. At this time, in the case where the input signals I₁₁and I₁₂are in a synchronized state, the phase adjustment amount R21 is represented by td1−td2.

Further, reference character R23 schematically depicts the delay amount (in other words, the phase adjustment amount) of a relative delay between the delay signal where a delay whose delay amount is 2 LSB is performed for the input signal I₁₁and the delay signal where a delay whose delay amount is 2 LSB is performed for the input signal I₁₂. At this time, in the case where the input signals I₁₁and I₁₂are in a synchronized state with each other, the phase adjustment amount R23 is represented by 2*td1−2*td2.

Here, in the case where Δtd=td1−td2 and besides td2<td1, it can be recognized that the relationship of Δtd<td2<td1 is satisfied. In particular, by utilizing such a feature of thephase adjustment circuit1010 as described above, it is possible to adjust the phase difference, for example, between the light source driving signal and the pixel driving signal (in other words, the relative delay) with a resolution finer than the resolutions td1 and td2 in adjustment of a delay performed for the driving signals. Consequently, with the distance image sensor according to the embodiment of the present disclosure, it is possible to adjust the phase difference between the light source driving signal and the pixel driving signal (namely, to synchronize the light source driving signal and the pixel driving signal with each other) with a resolution finer than the resolutions of the delay circuits that perform a delay for the driving signals.

It is to be noted that, in the present control example, the firstvariable delay circuit1011 corresponds to an example of the “first delay circuit” and the delay amount of a delay performed for the driving signal (in other words, the input signal to the circuit) by the first variable delay circuit1011 (namely, the delay amount whose delay adjustment resolution is td1) corresponds to an example of the “first delay circuit.” Further, the secondvariable delay circuit1013 corresponds to an example of the “second delay circuit,” and the delay amount of a delay performed for the driving signal by the second variable delay circuit1013 (namely, the delay amount whose delay adjustment resolution is td2) corresponds to an example of the “second delay amount.”

The first control example of the distance image sensor according to the embodiment of the present disclosure has been described with reference toFIGS.31 and32.

Second Control Example

Now, a second control example of the distance image sensor according to the embodiment of the present disclosure is described. For example,FIGS.33 and34 are explanatory views illustrating the second control example of the distance image sensor according to the embodiment of the present disclosure.

First, an overview of delay control according to the present control example is described with reference toFIG.33. In the present control example, one of a plurality of driving signals different from each other is delayed by a plurality of delay circuits having delay adjustment resolutions different from each other to control the relative delay between the plurality of driving signals. For example, inFIG.33, input signals I₂₁and I₂₂individually correspond to driving signals before the phase difference therebetween is adjusted, and output signals O₂₁and O₂₂individually correspond to driving signals after the phase difference between the input signals I₂₁and I₂₂is adjusted.Reference character1020 corresponds to thephase adjustment circuit1010 in the example depicted inFIG.31. In the present control example, thephase adjustment circuit1020 performs a plurality of kinds of delays for one of a plurality of driving signals inputted thereto to control the phase difference between the plurality of driving signals (namely, the delay amount of the relative delay).

Thephase adjustment circuit1020 includes a firstvariable delay circuit1021 and a secondvariable delay circuit1023 having delay adjustment resolutions different from each other. It is to be noted that the delay adjustment resolution of the firstvariable delay circuit1021 is represented by td1, and the delay adjustment resolution of the secondvariable delay circuit1023 is represented by td2. On the basis of such a configuration as described above, each of the firstvariable delay circuit1021 and the secondvariable delay circuit1023 performs a delay for the input signal I₂₁and outputs the delayed input signal I₂₁as the output signal O₂₁. At this time, the delay amount of the delay performed for the input signal I₂₁by the firstvariable delay circuit1021 is controlled in a unit of td1 on the basis of a delay controlling signal D₂₁. Meanwhile, the delay amount of the delay performed for the input signal I₁₁by the secondvariable delay circuit1023 is controlled in a unit of td2 on the basis of a delay controlling signal D22. It is to be noted that one of the input signals I₁₁and I₁₂corresponds to the light source driving signal before the delay is performed, and the other corresponds to the pixel driving signal before the delay is performed.

Referring toFIG.33, reference character R31 schematically depicts a delay amount of a relative delay between the input signals I₂₁and I₂₂(namely, the phase adjustment amount). Meanwhile, reference character R33 schematically depicts a delay amount of a relative delay between the output signals O₂₁and O₂₂. As can be recognized by comparison between the delay amounts R31 and R33, since a delay is performed for one of a plurality of inputted driving signals (namely, the input signals I₂₁and I₂₂) by thephase adjustment circuit1020, the relative delay amount between the driving signals (namely, the output signals O₁₁and O₁₂) to be outputted from thephase adjustment circuit1020 changes. At this time, the adjustment amount (phase adjustment amount) of a relative delay between the input signals I₂₁and I₂₂is determined on the basis of the delay amount applied to the input signal I₂₁in a unit of td1 by the firstvariable delay circuit1021 and the delay amount applied to the input signal I₂₁in a unit of td2 by the secondvariable delay circuit1023.

Here, a phase adjustment amount between controls in the case where the delay amounts to be applied by the firstvariable delay circuit1021 and the secondvariable delay circuit1023 for the input signal I₂₁in the example depicted inFIG.33 are controlled is described taking a particular example with reference toFIG.34. The example depicted on the upper side inFIG.34 depicts an example of a case in which, for the input signal I₂₁, a delay whose delay amount is 1 LSB is performed by the firstvariable delay circuit1021 first, and thereafter, a delay whose delay amount is 2 LSB is performed by the secondvariable delay circuit1023. In contrast, the example depicted on the lower side inFIG.34 depicts an example in which a delay whose delay amount is two LBS is performed by the firstvariable delay circuit1021 first, and thereafter, a delay whose delay amount is 1 LSB is performed by the secondvariable delay circuit1023.

Referring toFIG.34, reference character R41 schematically depicts a delay amount of the relative delay between the example depicted on the upper side and the example depicted on the lower side. At this time, the delay amount R41 is represented by (2*td1+td2)−(td1+2*td2)=td1−td2.

Here, in the case where Δtd=td1−td2 and td2<td1 are satisfied, it can be recognized that the relationship of Δtd<td2<td1 is satisfied. In particular, by utilizing such a feature of thephase adjustment circuit1020 as described above, it is possible to adjust the delay of one of the light source driving signal and the pixel driving signal with a resolution finer than the resolutions td1 and td2 relating to adjustment of a delay performed by each delay circuit. Consequently, with the distance image sensor according to the embodiment of the present disclosure, it is possible to adjust the phase difference between the light source driving signal and the pixel driving signal (namely, to synchronize the light source driving signal and the pixel driving signal with each other) with a resolution finer than the resolutions of the delay circuits that perform a delay for one of the light source driving signal and the pixel driving signal.

It is to be noted that, in the present control example, the firstvariable delay circuit1021 corresponds to an example of the “first delay circuit” and the delay amount of a delay performed for the driving signal by the first variable delay circuit1021 (namely, the delay amount whose delay adjustment resolution is td1) corresponds to an example of the “first delay amount.” Further, the secondvariable delay circuit1023 corresponds to an example of the “second delay circuit,” and the delay amount of a delay performed for the driving signal by the second variable delay circuit1023 (namely, the delay amount whose delay adjustment resolution is td2) corresponds to an example of the “second delay amount.”

The second control amount of the distance image sensor according to the embodiment of the present disclosure has been described with reference toFIGS.33 and34.

Configuration Example of Delay Circuit

Subsequently, an example of a variable delay circuit (for example, the first variable delay circuit and the second variable delay circuit) for delaying a driving signal for the light source apparatus or the sensor chip in the distance image sensor according to the embodiment of the present disclosure is described. For example, each ofFIGS.35 to38 is a view depicting an example of a schematic configuration of a variable delay circuit that can be applied to the distance image sensor according to the embodiment of the present disclosure.

FIG.35 depicts an example of a case in which a difference is provided between load capacitances of a first delay circuit and a second delay circuit to provide a delay difference between the first delay circuit and the second delay circuit. In particular, in the example depicted inFIG.35, the delay circuits are configured such that the load capacitance C1 of the first delay circuit and the load capacitance C2 of the second delay circuit satisfy a relationship of C1≠C2. This makes it possible to configure the delay circuits such that the delay time td1 of the first delay circuit (in other words, the delay adjustment resolution td1) and the delay time td2 of the second delay circuit (in other words, the delay adjustment resolution td2) satisfy the relationship of td1≠td2.

FIG.36 depicts an example of a case in which a delay difference is provided between a first delay circuit and a second delay circuit by providing a difference between the load resistances of the first delay circuit and the second delay circuit. In particular, in the example depicted inFIG.36, the delay circuits are configured such that the load resistance R1 of the first delay circuit and the load resistance R2 of the second delay circuit satisfy a relationship of R1≠R2. This makes it possible to configure the delay circuits such that the delay time td1 of the first delay circuit (in other words, the delay adjustment resolution td1) and the delay time td2 of the second delay circuit (in other words, the delay adjustment resolution td2) satisfy a relationship of td1≠td2.

FIG.37 depicts an example of a case in which a delay difference is provided between a first delay circuit and a second delay circuit by providing a difference between stage numbers of delay elements of the first delay circuit and the second delay circuit. In particular, in the example depicted inFIG.36, the delay circuits are configured such that the stage number N1 of the delay elements configuring the first delay circuit and the stage number N2 of the delay elements configuring the second delay circuit satisfy a relationship of N1≠N2. This makes it possible to configure the delay circuits such that the delay time td1 of the first delay circuit (in other words, the delay adjustment resolution td1) and the delay time td2 of the second delay circuit (in other words, the delay adjustment resolution td2) satisfy a relationship of td1≠td2.

FIG.38 depicts an example of a case in which a delay difference is provided between a first delay circuit and a second delay circuit by providing a difference between the sizes of the delay elements (for example, transistors) of the first delay circuit and the second delay circuit. In particular, in the example depicted inFIG.37, the delay circuits are configured such that the size W1 of the delay element configuring the first delay circuit and the size W2 of the delay element configuring the second delay circuit satisfy a relationship of W1≠W2. This makes it possible to configure the delay circuits such that the delay time td1 of the first delay circuit (in other words, the delay adjustment resolution td1) and the delay time td2 of the second delay circuit (in other words, the delay adjustment resolution td2) satisfy a relationship of td1≠td2.

It is to be noted that the examples described with reference toFIGS.35 to38 are examples to the last and do not necessarily restrict the configuration of a delay circuit (for example, the first delay circuit and the second delay circuit) applied to a distance image sensor according to the embodiment of the present disclosure. In particular, if it is possible to provide a delay difference between the first delay circuit and the second delay circuit (namely, to provide a difference in delay adjustment resolution), then the configuration of each of the first delay circuit and the second delay circuit is not restricted specifically. As a more particular example, a plurality of ones of the examples depicted inFIGS.35 to38 may be used in combination. Further, a delay difference may be provided between the first delay circuit and the second delay circuit on the basis of an idea different from those of the examples depicted inFIGS.35 to38.

First Configuration Example of Distance Image Sensor

Now, as a first configuration example of the distance image sensor according to the embodiment of the present disclosure, an example of a functional configuration of the distance image sensor is described. For example,FIG.39 is a functional block diagram depicting a first configuration example of the distance image sensor according to the embodiment of the present disclosure and especially depicts an example of a configuration of a sensor chip applied to the distance image sensor. It is to be noted that, in the following description, for the convenience of description, the distance image sensor according to the first configuration example is sometimes referred to as “distance image sensor1100” in order to distinguish the same from the other configuration examples.

Referring toFIG.39,reference character1101 denotes a sensor chip applied to thedistance image sensor1100 and corresponds, for example, to thesensor chip203 in thedistance image sensor201 described hereinabove with reference toFIG.27. Further, inFIG.39, alight source1171 and a lightsource driving circuit1173 correspond, for example, to the light source and the light source driving circuit of thelight source apparatus211 described hereinabove with reference toFIG.27.

Thesensor chip1101 includes apixel array1111, apixel driving circuit1113, a reading outcircuit1115, a PLL (Phase-Locked Loop)1120, an inputting and outputting (I/O)section1130, a drivingsignal generation circuit1140, aphase adjustment circuit1150 and acontrol circuit1160. Further, the drivingsignal generation circuit1140 includes a pixel drivingpulse generation circuit1141 and a light source drivingpulse generation circuit1143.

Thepixel array1111 corresponds to thepixel array section12 in thesensor chip11 described hereinabove. Meanwhile, thepixel driving circuit1113 corresponds to a circuit for driving the pixels of thepixel array1111 and corresponds, for example, to the globalcontrolling circuit13 or the rolling controllingcircuit14 in thesensor chip11 described hereinabove. Further, the reading outcircuit1115 corresponds to a circuit for reading out a sensor signal from each pixel of thepixel array1111 and corresponds, for example, to thecolumn ADC15 and so forth in thesensor chip11 described hereinabove. Therefore, detailed description of thepixel array1111,pixel driving circuit1113 and reading outcircuit1115 is omitted.

ThePLL1120 generates a reference signal (clock pulse) that makes a reference for controlling operation timings of the components of thesensor chip1101. In particular, the components in thesensor chip1101 operate in synchronism with the clock pulse generated by thePLL1120. ThePLL1120 supplies the clock pulse generated thereby to the drivingsignal generation circuit1140 and thecontrol circuit1160.

The pixel drivingpulse generation circuit1141 generates a pulse signal for controlling the driving timing of the pixel driving circuit1113 (namely, a pixel driving signal) on the basis of the clock pulse supplied thereto from thePLL1120. The pixel drivingpulse generation circuit1141 outputs the generated pixel driving signal to thephase adjustment circuit1150 positioned in the succeeding stage. Further, the light source drivingpulse generation circuit1143 generates a pulse signal for controlling the driving timing of the light source driving circuit1173 (namely, a light source driving signal) on the basis of the clock pulse supplied thereto from thePLL1120. The light source drivingpulse generation circuit1143 outputs the generated light source driving signal to thephase adjustment circuit1150 positioned in the succeeding stage. It is to be noted that the timings at which the pixel drivingpulse generation circuit1141 and the light source drivingpulse generation circuit1143 are to operate are controlled by thecontrol circuit1160.

Thephase adjustment circuit1150 delays at least one of the pixel driving signal outputted from the pixel drivingpulse generation circuit1141 or the light source driving signal outputted from the light source drivingpulse generation circuit1143 to adjust the phase difference between the pixel driving signal and the light source driving signal. Then, thephase adjustment circuit1150 supplies the light source driving signal after the phase adjustment to the lightsource driving circuit1173. Consequently, the timing at which the lightsource driving circuit1173 is to drive thelight source1171, namely, the timing at which thelight source1171 is to project pulse light, is controlled on the basis of the light source driving signal supplied from thephase adjustment circuit1150. Further, thephase adjustment circuit1150 supplies the pixel driving signal after the phase adjustment to thepixel driving circuit1113. Consequently, the timing at which thepixel driving circuit1113 is to drive each pixel of thepixel array1111, namely, the timing at which each pixel of thepixel array1111 is to detect the pulse light reflected by an imaging object, is controlled on the basis of the pixel driving signal supplied from thephase adjustment circuit1150. From the foregoing, it is possible to synchronize operation of thelight source1171 and operation of the sensor chip1101 (especially thepixel array1111 and the reading out circuit1115) with each other.

It is to be noted that the control relating to the adjustment of the phase difference between the pixel driving signal and the light source driving signal by thephase adjustment circuit1150 is, for example, described hereinabove as the first control example and the second control example. In other words, thephase adjustment circuit1150 can adjust the phase difference between the pixel driving signal and the light source driving signal with a resolution finer than the delay adjustment resolutions of the delay circuits that delay the pixel driving signal and the light source driving signal.

Consequently, for example, operation of the lightsource driving circuit1173 and operation of thepixel driving circuit1113 are controlled so as to be synchronized with each other. In particular, operation of thelight source1171 for projecting pulse light and operation of each of the pixels (sensor elements) of thepixel array1111 for detecting the pulse light reflected by an imaging object are controlled so as to be synchronized with each other. It is to be noted that the timing at which thephase adjustment circuit1150 is to operate is controlled by thecontrol circuit1160.

Thecontrol circuit1160 controls operation of the components of thesensor chip1101. For example, thecontrol circuit1160 controls operation timings of the drivingsignal generation circuit1140 and thephase adjustment circuit1150 on the basis of the clock pulse outputted from thePLL1120.

Further, thecontrol circuit1160 may measure the distance to an imaging object on the basis of a result of reading out of sensor signals from the pixels of the pixel array1111 (namely, of charge amounts accumulated in the pixels) by the reading outcircuit1115. In this case, thecontrol circuit1160 may output information according to a result of the measurement of the distance to the outside of thesensor chip1101 through the inputting andoutputting section1130.

The inputting andoutputting section1130 is an input/output interface forsensor chip1101 performing transmission and reception of information to and from an outside element. For example, information according to a reading out result of the sensor signal from each pixel of thepixel array1111 by the reading outcircuit1115 may be outputted to the outside of thesensor chip1101 through the inputting andoutputting section1130. Further, information according to a result of various arithmetic operations by thecontrol circuit1160 may be outputted to the outside of thesensor chip1101 through the inputting andoutputting section1130. For example, information according to a result of measurement of the distance to an imaging object by thecontrol circuit1160 may be outputted to the outside of thesensor chip1101 through the inputting andoutputting section1130 as described hereinabove.

It is to be noted that thepixel array1111 and the reading outcircuit1115 correspond to an example of the “light reception section” in measurement of the distance to an image object, and thelight source1171 corresponds to an example of the “light source” in measurement of the distance to an imaging object. Further, thephase adjustment circuit1150 corresponds to an example of the “control section” that controls the relative time difference (in other words, the phase difference) between the first timing at which the light reception section (each pixel of the pixel array1111) is to detect the light reception amount and the second timing at which the light source is to project light. Further, the configuration for measuring the distance to an imaging object on the basis of a sensor signal read out from each pixel of thepixel array1111 by the reading outcircuit1115 corresponds to an example of the “measurement section,” and, for example, thecontrol circuit1160 can correspond to this.

Further, the functional configuration described above is an example to the last, and if operation of the components is implemented, then the configuration of thedistance image sensor1100 is not necessarily restricted only to the example depicted inFIG.39. As a particular example, thesensor chip1101 and the components corresponding to the light source (namely, thelight source1171 and the light source driving circuit1173) may be configured integrally with each other.

Further, thesensor chip1101 may have the stacked structure described hereinabove. In this case, part of the components of thesensor chip1101 and the other components different from the part of the components may be provided on boards different from each other. As a more particular example, among the components of thesensor chip1101, thepixel array1111 and the components other than thepixel array1111 may be provided on boards different from each other.

Further, part of the components of thesensor chip1101 may be provided outside of thesensor chip1101. As a particular example, thePLL1120, drivingsignal generation circuit1140,phase adjustment circuit1150 andcontrol circuit1160 may be provided outside the sensor chip1101 (for example, in a different chip, electronic equipment, apparatus or the like provided for the control).

Further, of thephase adjustment circuit1150, part that applies a delay to the pixel driving signal and part that applies a delay to the light source driving signal may be provided on chips different from each other, in electronic equipment different from each other or in apparatus different from each other. As a particular example, part that applies a delay to the light source driving signal may be provided outside the sensor chip1101 (for example, on the light source apparatus side). It is to be noted that, in this case, the function of thephase adjustment circuit1150 can be implemented by interlinking of the part that applies a delay to the pixel driving signal and the part that applies a delay to the light source driving signal. As a particular example, by controlling the delay to be applied to the pixel driving signal in response to the delay applied to the light source driving signal, it is possible to control the phase difference between the pixel driving signal and the light source driving signal with a resolution finer than the delay adjustment resolutions for the delays.

As the first configuration example of the distance image sensor according to the embodiment of the present disclosure, an example of the functional configuration of the distance image sensor has been described with reference toFIG.39.

Second Configuration Example of Distance Image Sensor

Now, as a second configuration example of the distance image sensor according to the embodiment of the present disclosure, another example of the functional configuration of the distance image sensor is described. For example,FIG.40 is a functional block diagram depicting the second configuration example of the distance image sensor according to the embodiment of the present disclosure and especially depicts an example of a configuration of a sensor chip applied to the distance image sensor. It is to be noted that, in the following description, for the convenience of description, the distance image sensor according to the second configuration example is sometimes referred to as “distance image sensor1200” in order to distinguish the same from any other configuration example.

Referring toFIG.40,reference numeral1201 denotes a sensor chip applied to thedistance image sensor1200 and corresponds, for example, to thesensor chip203 in thedistance image sensor201 described hereinabove with reference toFIG.27. Further, inFIG.40, alight source1271 and a lightsource driving circuit1273 correspond, for example, to the light source and the light source driving circuit of thelight source apparatus211 described hereinabove with reference toFIG.27.

Thesensor chip1201 includes apixel array1211, apixel driving circuit1213, a reading outcircuit1215, aPLL1220, an inputting and outputting circuit (I/O)1230, a drivingsignal generation circuit1240, aphase adjustment circuit1250 and acontrol circuit1260. Further, the drivingsignal generation circuit1240 includes a pixel drivingpulse generation circuit1241 and a light source drivingpulse generation circuit1243. It is to be noted that thepixel array1211,pixel driving circuit1213, reading outcircuit1215,PLL1220 and inputting and outputtingcircuit1230 are substantially similar to thepixel array1111,pixel driving circuit1113, reading outcircuit1115,PLL1120 and inputting andoutputting section1130 in thedistance image sensor1100 described hereinabove with reference toFIG.39. Therefore, in the following description, description is given focusing on part of the functional configuration of thedistance image sensor1200 substantially different from that of thedistance image sensor1100 described hereinabove while detailed description of substantially similar portions to those of thedistance image sensor1200 is omitted.

ThePLL1220 generates reference signals (clock pulses) that make a reference for controlling operation timings of the components of thesensor chip1201 and outputs the clock pulses to thephase adjustment circuit1250 and thecontrol circuit1260.

Thephase adjustment circuit1250 supplies the clock pulses supplied thereto from thePLL1220 individually to the pixel drivingpulse generation circuit1241 and the light source drivingpulse generation circuit1243 positioned in the succeeding stage. It is to be noted that, in the following description, for the convenience of description, the clock pulse supplied to the pixel drivingpulse generation circuit1241 is referred to also as “first clock pulse,” and the clock pulse supplied to the light source drivingpulse generation circuit1243 is referred to also as “second clock pulse.” At this time, thephase adjustment circuit1250 adjusts the phase difference between the first clock pulse and the second clock pulse by delaying at least one of the first clock pulse or the second clock pulse. In particular, the first clock pulse and the second clock pulse having the adjusted phases are supplied to the light source drivingpulse generation circuit1243 and the pixel drivingpulse generation circuit1241, respectively.

It is to be noted that, in the control for adjustment of the phase difference between the first clock pulse and the second clock pulse by thephase adjustment circuit1250 is such as described above, for example, as the first control example and the second control example. In particular, thephase adjustment circuit1250 can adjust the phase difference between the first clock pulse and the second clock pulse with a resolution finer than the delay adjustment resolution of the delay circuits that delay the clock pulses supplied from thePLL1220.

The pixel drivingpulse generation circuit1241 generates a pulse signal for controlling the driving timing of the pixel driving circuit1213 (namely, a pixel driving signal) on the basis of the first clock pulse supplied from thephase adjustment circuit1250. The pixel drivingpulse generation circuit1141 outputs the generated pixel driving signal to thepixel driving circuit1213. Further, the light source drivingpulse generation circuit1243 generates a pulse signal for controlling the driving timing of the light source driving circuit1273 (namely, a light source driving signal) on the basis of the second clock pulse supplied from thephase adjustment circuit1250. The light source drivingpulse generation circuit1243 outputs the generated light source driving signal to the lightsource driving circuit1273.

It is to be noted that, as described hereinabove, the phase difference between the first clock pulse and the second clock pulse is adjusted by thephase adjustment circuit1250. Therefore, the phase difference between the light source driving signal generated on the basis of the first clock pulse and the pixel driving signal generated on the basis of the second clock pulse is adjusted together with the phase difference between the first clock pulse and the second clock pulse. In particular, also it is possible to synchronize the timing at which thelight source1171 is to project pulse light and the timing at which each of the pixels of thepixel array1111 detects the pulse light reflected by an imaging object with each other in response to the phase difference between the light source driving signal and the pixel driving signal (in other words, the phase difference between the first clock pulse and the second clock pulse).

The operation timings of thephase adjustment circuit1250 and the drivingsignal generation circuit1240 are controlled on the basis of the clock pulses outputted from thePLL1220 by thecontrol circuit1260. Further, thecontrol circuit1260 may measure the distance to an imaging object on the basis of a result of reading out of sensor signals from the pixels of the pixel array1211 (namely, of the charging amounts accumulated in the pixels) by the reading outcircuit1215. In this case, thecontrol circuit1260 may output information according to a result of the measurement of the distance to the outside of thesensor chip1101 through the inputting and outputtingcircuit1230.

Further, similarly as in the example described hereinabove with reference toFIG.39, the functional configuration described above is an example to the last, and if operation of the components is implemented, then the functional configuration of thedistance image sensor1200 is not necessarily restricted only to the example depicted inFIG.40.

As the second configuration of the distance image sensor according to the embodiment of the present disclosure, another example of the functional configuration of the distance image sensor has been described with reference toFIG.40.

Third Configuration Example of Distance Image Sensor

Now, as a third configuration example of the distance image sensor according to the embodiment of the present disclosure, a further example of the functional configuration of the distance image sensor is described. For example,FIG.41 is a functional block diagram depicting the third configuration example of the distance image sensor according to the embodiment of the present disclosure and especially depicts an example of a configuration of a sensor chip applied to the distance image sensor. It is to be noted that, in the following description, for the convenience of description, the distance image sensor according to the third configuration example is sometimes referred to as “distance image sensor1300” in order to distinguish the same from any other configuration example.

Referring toFIG.41,reference numeral1301 denotes a sensor chip applied to thedistance image sensor1300 and corresponds, for example, to thesensor chip203 in thedistance image sensor201 described hereinabove with reference toFIG.27. Further, inFIG.41, alight source1371 and a lightsource driving circuit1373 correspond, for example, to the light source and the light source driving circuit of thelight source apparatus211 described with reference toFIG.27.

Thesensor chip1301 includes apixel array1311, apixel driving circuit1313, a reading outcircuit1315, aPLL1320, an inputting and outputting section (I/O)1330, a drivingsignal generation circuit1340, aphase adjustment circuit1350, acontrol circuit1360 and a distance errorarithmetic operation circuit1380. It is to be noted that thepixel array1311,pixel driving circuit1313 and reading outcircuit1315 and thePLL1320, inputting andoutputting section1330 and drivingsignal generation circuit1340 are substantially similar to thepixel array1111,pixel driving circuit1113, reading outcircuit1115,PLL1120, inputting andoutputting section1130 and drivingsignal generation circuit1140 in thedistance image sensor1100 described hereinabove with reference toFIG.39. Therefore, in the following description, in regard to the functional configuration of thedistance image sensor1300, description is given focusing on part different from that of thedistance image sensor1100 described hereinabove while detailed description of part substantially similar to that of thedistance image sensor1100 is omitted.

The distance errorarithmetic operation circuit1380 calculates an error in measurement of the distance to an imaging object on the basis of a reading out result of the sensor signals from the pixels of the pixel array1211 (namely, of charge amounts accumulated in the pixels) by the reading outcircuit1215 and feeds back a calculation result of the error to thephase adjustment circuit1350. As a particular example, the distance errorarithmetic operation circuit1380 acquires an ideal value of a reading out result of the sensor signal relating to the measurement of a distance from thecontrol circuit1360 and calculates an error between the reading out result of the sensor signal outputted from the reading outcircuit1215 and the acquired ideal value. Then, the distance errorarithmetic operation circuit1380 outputs the calculated error to thephase adjustment circuit1350. In this case, thephase adjustment circuit1350 controls the phase difference between the light source driving signal and the pixel driving signal on the basis of the error fed back from the distance errorarithmetic operation circuit1380 such that the error decreases (namely, the reading out result of the sensor signal approaches the ideal value). At this time, thephase adjustment circuit1350 can adjust the phase difference between the light source driving signal and the pixel driving signal with a resolution finer than the delay adjustment resolutions of the delay circuits that delay the light source driving signal and the pixel driving signal.

It is to be noted that the method of thecontrol circuit1360 for deriving the ideal value is not specifically limited. For example, in the case where an imaging target the distance to which is known is imaged as in a mode in which a measurement result of the distance is corrected or a like mode, information according to the known distance may be outputted as the ideal value to the distance errorarithmetic operation circuit1380. Further, as another example, thecontrol circuit1360 may calculate the ideal value by utilizing a detection result by some other detection device like a GPS device. Naturally, the foregoing is an example to the last, and if the ideal value can be derived or determined, then the method therefor is not specifically limited. Further, the distance errorarithmetic operation circuit1380 corresponds to an example of the “error arithmetical operation section.”

It is to be noted that the foregoing description is directed to an example of a case in which the distance errorarithmetic operation circuit1380 is added to thedistance image sensor1100 depicted inFIG.39 such that an error relating to measurement of the distance to an imaging object is fed back to thephase adjustment circuit1350 in response to a reading out result of a sensor signal from each pixel. Meanwhile, also in regard to thedistance image sensor1200 depicted inFIG.40, by adding the distance errorarithmetic operation circuit1380, an error in measurement of the distance to an imaging object can be similarly fed back to thephase adjustment circuit1250 in response to a reading out result of a sensor signal from each pixel.

Further, similarly to the example described hereinabove with reference toFIG.39, the functional configuration described above is an example to the last, and if operation of the components is implemented, then the configuration of thedistance image sensor1300 is not necessarily limited only to the example depicted inFIG.41.

As the third configuration example of the distance image sensor according to the embodiment of the present disclosure, a further example of the functional configuration of the distance image sensor has been described with reference toFIG.41.

<<4. Usage Example and Application Example>>

Subsequently, usage examples and application examples of the technology according to the present disclosure are described.

<Usage Example of Image Sensor>

FIG.42 is a view depicting usage examples in which the image sensor (imaging element) described hereinabove is used.

The image sensor described above can be used in various cases in which visible light, infrared light, ultraviolet light, an X-ray or the like is sensed, for example, as described below.

• • Apparatus that captures an image to be used for appreciation such as a digital camera, a portable apparatus with a camera function and so forth
  • Apparatus used for traffic such as an automotive sensor for imaging the front or back, surroundings, inside or the like of an automobile for safe driving such as automatic stopping, recognition of the state of the driver and so forth, a security camera for monitoring a traveling vehicle or the road, a distance measurement sensor for performing distance measurement between automobiles and so forth
  • Apparatus for use with household appliances such as a TV set, a refrigerator or an air conditioner for imaging a gesture of a user and performing apparatus operation in accordance with the gesture
  • Apparatus for medical use or healthcare use such as an endoscope, an apparatus for performing angiography by reception of infrared light or the like
  • Apparatus for use for security such as a surveillance camera for security applications, a camera for a person authentication application or the like
  • Apparatus for cosmetic use such as a skin measuring instrument for imaging the skin, a microscope for imaging the scalp or the like
  • Apparatus for use for sports such as an action camera, a wearable camera or the like for sports applications
  • Apparatus for agricultural applications such as a camera for monitoring the state of a field or crops

Further, the distance image sensor according to the embodiment of the present disclosure can be used for various apparatus that provide various functions utilizing, for example, a distance measurement technology such as the ToF. As an example of such apparatus, an apparatus configured for movement by being held by a user, for example, a smartphone, a wearable device (for example, a wristwatch type or glasses-type device), an HMD (Head Mounted Display) or the like can be listed. Further, as another example of the apparatus described above, a moving body such as a vehicle and an apparatus configured such that it itself is movable like a drone, a robot (for example, an industrial robot, an autonomously actable robot or the like), FA (Factor Automation) equipment, agricultural equipment or the like can be listed. Naturally, the foregoing is an example to the last, and the apparatus to which the distance image sensor is applied is not specifically restricted if it can utilize a distance measurement result by the distance image sensor according to the embodiment of the present disclosure.

<Application Example to Endoscopic Surgery System>

The technology according to the present disclosure (present technology) can be applied to various products. For example, the technology according to the present disclosure may be applied to an endoscopic surgery system.

FIG.43 is a view depicting an example of a schematic configuration of an endoscopic surgery system to which the technology according to an embodiment of the present disclosure (present technology) can be applied.

InFIG.43, a state is illustrated in which a surgeon (medical doctor)11131 is using anendoscopic surgery system11000 to perform surgery for apatient11132 on apatient bed11133. As depicted, theendoscopic surgery system11000 includes anendoscope11100, othersurgical tools11110 such as apneumoperitoneum tube11111 and anenergy device11112, a supportingarm apparatus11120 which supports theendoscope11100 thereon, and acart11200 on which various apparatus for endoscopic surgery are mounted.

Theendoscope11100 includes alens barrel11101 having a region of a predetermined length from a distal end thereof to be inserted into a body cavity of thepatient11132, and acamera head11102 connected to a proximal end of thelens barrel11101. In the example depicted, theendoscope11100 is depicted which includes as a rigid endoscope having thelens barrel11101 of the hard type. However, theendoscope11100 may otherwise be included as a flexible endoscope having thelens barrel11101 of the flexible type.

Thelens barrel11101 has, at a distal end thereof, an opening in which an objective lens is fitted. A light source apparatus11203 is connected to theendoscope11100 such that light generated by the light source apparatus11203 is introduced to a distal end of thelens barrel11101 by a light guide extending in the inside of thelens barrel11101 and is irradiated toward an observation target in a body cavity of thepatient11132 through the objective lens. It is to be noted that theendoscope11100 may be a forward-viewing endoscope or may be an oblique-viewing endoscope or a side-viewing endoscope.

An optical system and an image pickup element are provided in the inside of thecamera head11102 such that reflected light (observation light) from the observation target is condensed on the image pickup element by the optical system. The observation light is photo-electrically converted by the image pickup element to generate an electric signal corresponding to the observation light, namely, an image signal corresponding to an observation image. The image signal is transmitted as RAW data to aCCU11201.

TheCCU11201 includes a central processing unit (CPU), a graphics processing unit (GPU) or the like and integrally controls operation of theendoscope11100 and adisplay apparatus11202. Further, theCCU11201 receives an image signal from thecamera head11102 and performs, for the image signal, various image processes for displaying an image based on the image signal such as, for example, a development process (demosaic process).

Thedisplay apparatus11202 displays thereon an image based on an image signal, for which the image processes have been performed by theCCU11201, under the control of theCCU11201.

The light source apparatus11203 includes a light source such as, for example, a LED (Light Emitting Diode) and supplies irradiation light upon imaging of a surgical region to theendoscope11100.

Aninputting apparatus11204 is an input interface for theendoscopic surgery system11000. A user can perform inputting of various kinds of information or instruction inputting to theendoscopic surgery system11000 through the inputtingapparatus11204. For example, the user would input an instruction or a like to change an image pickup condition (type of irradiation light, magnification, focal distance or the like) by theendoscope11100.

A treatment tool controlling apparatus11205 controls driving of theenergy device11112 for cautery or incision of a tissue, sealing of a blood vessel or the like. A pneumoperitoneum apparatus11206 feeds gas into a body cavity of thepatient11132 through thepneumoperitoneum tube11111 to inflate the body cavity in order to secure the field of view of theendoscope11100 and secure the working space for the surgeon. Arecorder11207 is an apparatus capable of recording various kinds of information relating to surgery. Aprinter11208 is an apparatus capable of printing various kinds of information relating to surgery in various forms such as a text, an image or a graph.

It is to be noted that the light source apparatus11203 which supplies irradiation light when a surgical region is to be imaged to theendoscope11100 may include a white light source which includes, for example, an LED, a laser light source or a combination of them. Where a white light source includes a combination of red, green, and blue (RGB) laser light sources, since the output intensity and the output timing can be controlled with a high degree of accuracy for each color (each wavelength), adjustment of the white balance of a picked up image can be performed by the light source apparatus11203. Further, in this case, if laser beams from the respective RGB laser light sources are irradiated time-divisionally on an observation target and driving of the image pickup elements of thecamera head11102 are controlled in synchronism with the irradiation timings. Then images individually corresponding to the R, G and B colors can be also picked up time-divisionally. According to this method, a color image can be obtained even if color filters are not provided for the image pickup element.

Further, the light source apparatus11203 may be controlled such that the intensity of light to be outputted is changed for each predetermined time. By controlling driving of the image pickup element of thecamera head11102 in synchronism with the timing of the change of the intensity of light to acquire images time-divisionally and synthesizing the images, an image of a high dynamic range free from underexposed blocked up shadows and overexposed highlights can be created.

Further, the light source apparatus11203 may be configured to supply light of a predetermined wavelength band ready for special light observation. In special light observation, for example, by utilizing the wavelength dependency of absorption of light in a body tissue to irradiate light of a narrow band in comparison with irradiation light upon ordinary observation (namely, white light), narrow band observation (narrow band imaging) of imaging a predetermined tissue such as a blood vessel of a superficial portion of the mucous membrane or the like in a high contrast is performed. Alternatively, in special light observation, fluorescent observation for obtaining an image from fluorescent light generated by irradiation of excitation light may be performed. In fluorescent observation, it is possible to perform observation of fluorescent light from a body tissue by irradiating excitation light on the body tissue (autofluorescence observation) or to obtain a fluorescent light image by locally injecting a reagent such as indocyanine green (ICG) into a body tissue and irradiating excitation light corresponding to a fluorescent light wavelength of the reagent upon the body tissue. The light source apparatus11203 can be configured to supply such narrow-band light and/or excitation light suitable for special light observation as described above.

FIG.44 is a block diagram depicting an example of a functional configuration of thecamera head11102 and theCCU11201 depicted inFIG.43.

Thecamera head11102 includes alens unit11401, animage pickup unit11402, adriving unit11403, acommunication unit11404 and a camerahead controlling unit11405. TheCCU11201 includes acommunication unit11411, animage processing unit11412 and acontrol unit11413. Thecamera head11102 and theCCU11201 are connected for communication to each other by atransmission cable11400.

Thelens unit11401 is an optical system, provided at a connecting location to thelens barrel11101. Observation light taken in from a distal end of thelens barrel11101 is guided to thecamera head11102 and introduced into thelens unit11401. Thelens unit11401 includes a combination of a plurality of lenses including a zoom lens and a focusing lens.

Animage pickup unit11402 includes the image pickup element. The number of image pickup elements which is included by theimage pickup unit11402 may be one (single-plate type) or a plural number (multi-plate type). Where theimage pickup unit11402 is configured as that of the multi-plate type, for example, image signals corresponding to respective R, G and B are generated by the image pickup elements, and the image signals may be synthesized to obtain a color image. Theimage pickup unit11402 may also be configured so as to have a pair of image pickup elements for acquiring respective image signals for the right eye and the left eye ready for three dimensional (3D) display. If 3D display is performed, then the depth of a living body tissue in a surgical region can be comprehended more accurately by thesurgeon11131. It is to be noted that, where theimage pickup unit11402 is configured as that of stereoscopic type, a plurality of systems oflens units11401 are provided corresponding to the individual image pickup elements.

Further, theimage pickup unit11402 may not necessarily be provided on thecamera head11102. For example, theimage pickup unit11402 may be provided immediately behind the objective lens in the inside of thelens barrel11101.

The drivingunit11403 includes an actuator and moves the zoom lens and the focusing lens of thelens unit11401 by a predetermined distance along an optical axis under the control of the camerahead controlling unit11405. Consequently, the magnification and the focal point of a picked up image by theimage pickup unit11402 can be adjusted suitably.

Thecommunication unit11404 includes a communication apparatus for transmitting and receiving various kinds of information to and from theCCU11201. Thecommunication unit11404 transmits an image signal acquired from theimage pickup unit11402 as RAW data to theCCU11201 through thetransmission cable11400.

In addition, thecommunication unit11404 receives a control signal for controlling driving of thecamera head11102 from theCCU11201 and supplies the control signal to the camerahead controlling unit11405. The control signal includes information relating to image pickup conditions such as, for example, information that a frame rate of a picked up image is designated, information that an exposure value upon image picking up is designated and/or information that a magnification and a focal point of a picked up image are designated.

It is to be noted that the image pickup conditions such as the frame rate, exposure value, magnification or focal point may be designated by the user or may be set automatically by thecontrol unit11413 of theCCU11201 on the basis of an acquired image signal. In the latter case, an auto exposure (AE) function, an auto focus (AF) function and an auto white balance (AWB) function are incorporated in theendoscope11100.

The camerahead controlling unit11405 controls driving of thecamera head11102 on the basis of a control signal from theCCU11201 received through thecommunication unit11404.

Thecommunication unit11411 includes a communication apparatus for transmitting and receiving various kinds of information to and from thecamera head11102. Thecommunication unit11411 receives an image signal transmitted thereto from thecamera head11102 through thetransmission cable11400.

Further, thecommunication unit11411 transmits a control signal for controlling driving of thecamera head11102 to thecamera head11102. The image signal and the control signal can be transmitted by electrical communication, optical communication or the like.

Theimage processing unit11412 performs various image processes for an image signal in the form of RAW data transmitted thereto from thecamera head11102.

Thecontrol unit11413 performs various kinds of control relating to image picking up of a surgical region or the like by theendoscope11100 and display of a picked up image obtained by image picking up of the surgical region or the like. For example, thecontrol unit11413 creates a control signal for controlling driving of thecamera head11102.

Further, thecontrol unit11413 controls, on the basis of an image signal for which image processes have been performed by theimage processing unit11412, thedisplay apparatus11202 to display a picked up image in which the surgical region or the like is imaged. Thereupon, thecontrol unit11413 may recognize various objects in the picked up image using various image recognition technologies. For example, thecontrol unit11413 can recognize a surgical tool such as forceps, a particular living body region, bleeding, mist when theenergy device11112 is used and so forth by detecting the shape, color and so forth of edges of objects included in a picked up image. Thecontrol unit11413 may cause, when it controls thedisplay apparatus11202 to display a picked up image, various kinds of surgery supporting information to be displayed in an overlapping manner with an image of the surgical region using a result of the recognition. Where surgery supporting information is displayed in an overlapping manner and presented to thesurgeon11131, the burden on thesurgeon11131 can be reduced and thesurgeon11131 can proceed with the surgery with certainty.

Thetransmission cable11400 which connects thecamera head11102 and theCCU11201 to each other is an electric signal cable ready for communication of an electric signal, an optical fiber ready for optical communication or a composite cable ready for both of electrical and optical communications.

Here, while, in the example depicted, communication is performed by wired communication using thetransmission cable11400, the communication between thecamera head11102 and theCCU11201 may be performed by wireless communication.

An example of an endoscopic surgery system to which the technology according to the present disclosure can be applied has been described. The technology according to the present disclosure can be applied, from within the configuration described above, for example, to theendoscope11100, (theimage pickup unit11402 of) thecamera head11102, (theimage processing unit11412 of) theCCU11201 and so forth.

It is to be noted here that, while an endoscopic surgery system has been described as an example, the technology according to the present disclosure may be applied, for example, to a microscopic surgery system or the like.

<Application Example of Moving Body>

The technology according to the present disclosure (present technology) can be applied to various products. For example, the technology according to the present disclosure may be implemented as an apparatus that is incorporated in any type of moving body such as an automobile, an electric car, a hybrid electric car, a motorcycle, a bicycle, a personal mobility, an airplane, a drone, a ship, a robot and so forth.

FIG.45 is a block diagram depicting an example of schematic configuration of a vehicle control system as an example of a mobile body control system to which the technology according to an embodiment of the present disclosure can be applied.

The vehicle control system12000 includes a plurality of electronic control units connected to each other via acommunication network12001. In the example depicted inFIG.45, the vehicle control system12000 includes a drivingsystem control unit12010, a bodysystem control unit12020, an outside-vehicleinformation detecting unit12030, an in-vehicleinformation detecting unit12040, and anintegrated control unit12050. In addition, amicrocomputer12051, a sound/image output section12052, and a vehicle-mounted network interface (I/F)12053 are illustrated as a functional configuration of theintegrated control unit12050.

The drivingsystem control unit12010 controls the operation of devices related to the driving system of the vehicle in accordance with various kinds of programs. For example, the drivingsystem control unit12010 functions as a control device for a driving force generating device for generating the driving force of the vehicle, such as an internal combustion engine, a driving motor, or the like, a driving force transmitting mechanism for transmitting the driving force to wheels, a steering mechanism for adjusting the steering angle of the vehicle, a braking device for generating the braking force of the vehicle, and the like.

The bodysystem control unit12020 controls the operation of various kinds of devices provided to a vehicle body in accordance with various kinds of programs. For example, the bodysystem control unit12020 functions as a control device for a keyless entry system, a smart key system, a power window device, or various kinds of lamps such as a headlamp, a backup lamp, a brake lamp, a turn signal, a fog lamp, or the like. In this case, radio waves transmitted from a mobile device as an alternative to a key or signals of various kinds of switches can be input to the bodysystem control unit12020. The bodysystem control unit12020 receives these input radio waves or signals, and controls a door lock device, the power window device, the lamps, or the like of the vehicle.

The outside-vehicleinformation detecting unit12030 detects information about the outside of the vehicle including the vehicle control system12000. For example, the outside-vehicleinformation detecting unit12030 is connected with animaging section12031. The outside-vehicleinformation detecting unit12030 makes theimaging section12031 image an image of the outside of the vehicle, and receives the imaged image. On the basis of the received image, the outside-vehicleinformation detecting unit12030 may perform processing of detecting an object such as a human, a vehicle, an obstacle, a sign, a character on a road surface, or the like, or processing of detecting a distance thereto.

Theimaging section12031 is an optical sensor that receives light, and which outputs an electric signal corresponding to a received light amount of the light. Theimaging section12031 can output the electric signal as an image, or can output the electric signal as information about a measured distance. In addition, the light received by theimaging section12031 may be visible light, or may be invisible light such as infrared rays or the like.

The in-vehicleinformation detecting unit12040 detects information about the inside of the vehicle. The in-vehicleinformation detecting unit12040 is, for example, connected with a driverstate detecting section12041 that detects the state of a driver. The driverstate detecting section12041, for example, includes a camera that images the driver. On the basis of detection information input from the driverstate detecting section12041, the in-vehicleinformation detecting unit12040 may calculate a degree of fatigue of the driver or a degree of concentration of the driver, or may determine whether the driver is dozing.

Themicrocomputer12051 can calculate a control target value for the driving force generating device, the steering mechanism, or the braking device on the basis of the information about the inside or outside of the vehicle which information is obtained by the outside-vehicleinformation detecting unit12030 or the in-vehicleinformation detecting unit12040, and output a control command to the drivingsystem control unit12010. For example, themicrocomputer12051 can perform cooperative control intended to implement functions of an advanced driver assistance system (ADAS) which functions include collision avoidance or shock mitigation for the vehicle, following driving based on a following distance, vehicle speed maintaining driving, a warning of collision of the vehicle, a warning of deviation of the vehicle from a lane, or the like.

In addition, themicrocomputer12051 can perform cooperative control intended for automatic driving, which makes the vehicle to travel autonomously without depending on the operation of the driver, or the like, by controlling the driving force generating device, the steering mechanism, the braking device, or the like on the basis of the information about the outside or inside of the vehicle which information is obtained by the outside-vehicleinformation detecting unit12030 or the in-vehicleinformation detecting unit12040.

In addition, themicrocomputer12051 can output a control command to the bodysystem control unit12020 on the basis of the information about the outside of the vehicle which information is obtained by the outside-vehicleinformation detecting unit12030. For example, themicrocomputer12051 can perform cooperative control intended to prevent a glare by controlling the headlamp so as to change from a high beam to a low beam, for example, in accordance with the position of a preceding vehicle or an oncoming vehicle detected by the outside-vehicleinformation detecting unit12030.

The sound/image output section12052 transmits an output signal of at least one of a sound or an image to an output device capable of visually or auditorily notifying information to an occupant of the vehicle or the outside of the vehicle. In the example ofFIG.45, anaudio speaker12061, adisplay section12062, and aninstrument panel12063 are illustrated as the output device. Thedisplay section12062 may, for example, include at least one of an on-board display or a head-up display.

FIG.46 is a diagram depicting an example of the installation position of theimaging section12031.

InFIG.46, on thevehicle12100, theimaging section12031 includesimaging sections12101,12102,12103,12104, and12105.

Theimaging sections12101,12102,12103,12104, and12105 are, for example, disposed at positions on a front nose, sideview mirrors, a rear bumper, and a back door of thevehicle12100 as well as a position on an upper portion of a windshield within the interior of the vehicle. Theimaging section12101 provided to the front nose and theimaging section12105 provided to the upper portion of the windshield within the interior of the vehicle obtain mainly an image of the front of thevehicle12100. Theimaging sections12102 and12103 provided to the sideview mirrors obtain mainly an image of the sides of thevehicle12100. The image of the front of thevehicle12100. Theimaging sections12101 and12105 provided to the rear bumper or the back door obtains mainly an image of the rear of thevehicle12100. The image of the front obtained by theimaging sections12101 and12105 is used mainly to detect a preceding vehicle, a pedestrian, an obstacle, a signal, a traffic sign, a lane, or the like.

Incidentally,FIG.46 depicts an example of photographing ranges of theimaging sections12101 to12104. Animaging range12111 represents the imaging range of theimaging section12101 provided to the front nose. Imaging ranges12112 and12113 respectively represent the imaging ranges of theimaging sections12102 and12103 provided to the sideview mirrors. An imaging range12114 represents the imaging range of theimaging section12104 provided to the rear bumper or the back door. A bird's-eye image of thevehicle12100 as viewed from above is obtained by superimposing image data imaged by theimaging sections12101 to12104, for example.

At least one of theimaging sections12101 to12104 may have a function of obtaining distance information. For example, at least one of theimaging sections12101 to12104 may be a stereo camera constituted of a plurality of imaging elements, or may be an imaging element having pixels for phase difference detection.

For example, themicrocomputer12051 can determine a distance to each three-dimensional object within the imaging ranges12111 to12114 and a temporal change in the distance (relative speed with respect to the vehicle12100) on the basis of the distance information obtained from theimaging sections12101 to12104, and thereby extract, as a preceding vehicle, a nearest three-dimensional object in particular that is present on a traveling path of thevehicle12100 and which travels in substantially the same direction as thevehicle12100 at a predetermined speed (for example, equal to or more than 0 km/hour). Further, themicrocomputer12051 can set a following distance to be maintained in front of a preceding vehicle in advance, and perform automatic brake control (including following stop control), automatic acceleration control (including following start control), or the like. It is thus possible to perform cooperative control intended for automatic driving that makes the vehicle travel autonomously without depending on the operation of the driver or the like.

For example, themicrocomputer12051 can classify three-dimensional object data on three-dimensional objects into three-dimensional object data of a two-wheeled vehicle, a standard-sized vehicle, a large-sized vehicle, a pedestrian, a utility pole, and other three-dimensional objects on the basis of the distance information obtained from theimaging sections12101 to12104, extract the classified three-dimensional object data, and use the extracted three-dimensional object data for automatic avoidance of an obstacle. For example, themicrocomputer12051 identifies obstacles around thevehicle12100 as obstacles that the driver of thevehicle12100 can recognize visually and obstacles that are difficult for the driver of thevehicle12100 to recognize visually. Then, themicrocomputer12051 determines a collision risk indicating a risk of collision with each obstacle. In a situation in which the collision risk is equal to or higher than a set value and there is thus a possibility of collision, themicrocomputer12051 outputs a warning to the driver via theaudio speaker12061 or thedisplay section12062, and performs forced deceleration or avoidance steering via the drivingsystem control unit12010. Themicrocomputer12051 can thereby assist in driving to avoid collision.

At least one of theimaging sections12101 to12104 may be an infrared camera that detects infrared rays. Themicrocomputer12051 can, for example, recognize a pedestrian by determining whether or not there is a pedestrian in imaged images of theimaging sections12101 to12104. Such recognition of a pedestrian is, for example, performed by a procedure of extracting characteristic points in the imaged images of theimaging sections12101 to12104 as infrared cameras and a procedure of determining whether or not it is the pedestrian by performing pattern matching processing on a series of characteristic points representing the contour of the object. When themicrocomputer12051 determines that there is a pedestrian in the imaged images of theimaging sections12101 to12104, and thus recognizes the pedestrian, the sound/image output section12052 controls thedisplay section12062 so that a square contour line for emphasis is displayed so as to be superimposed on the recognized pedestrian. The sound/image output section12052 may also control thedisplay section12062 so that an icon or the like representing the pedestrian is displayed at a desired position.

An example of a vehicle control system to which the technology according to the present disclosure can be applied has been described. The technology according to the present disclosure can be applied to theimaging section12031 or the like in the configuration described above.

<<5. Conclusion>>

As described above, in the distance image sensor according to the embodiment of the present disclosure, the light reception section receives light projected from the light source and reflected by an imaging object to detect, for every predetermined detection period, a reception light amount of the reflected light within the detection period. Further, the measurement section measures the distance to the imaging object on the basis of the reception light amount. Further, the control section applies each of a first delay amount and a second delay amount between which a resolution in control is different to control of one of a first timing at which the light reception section is to detect the light reception apparatus and a second timing at which the light source is to project light. On the basis of such a configuration as just described, the control section controls the relative time difference between the first timing and the second timing with a resolution finer than the resolutions of the first delay amount and the second delay amount.

By such a configuration as described above, it is possible to synthesize operation of the light source and operation of the light reception section with each other with a higher degree of accuracy in comparison with an alternative case in which the relative time difference between the first timing and the second timing is controlled on the basis of only one of the first delay amount and the second delay amount. In other words, with the distance image sensor according to the embodiment of the present disclosure, it becomes possible to further reduce the influence of an error caused by a resolution in processing relating to measurement of the distance, and after all, it becomes possible to anticipate an effect of further improving the accuracy relating to measurement of the distance.

Although the preferred embodiments of the present disclosure have been described in detail with reference to the accompanying drawings, the technical scope of the present disclosure is not limited to such embodiments as described above. It is apparent that those who have common knowledge in the technical field of the present disclosure can conceive various alternations or modifications without departing from the technical scope described in the claims, and it is recognized that also they naturally belong to the technical scope of the present disclosure.

As a particular example, the number of types of delay amounts that are applied to control of a timing at which the reception section is to detect a light reception amount or a timing at which the light source is to project light is not limited to two. In particular, each of three or more types of delay amounts whose delay adjustment resolutions are different from each other may be applied to control of the timing at which the light reception section is to detect a reception light amount or the timing at which the light source is to project light. As a more particular example, the number of types of delay amounts to be used for the control may be determined in response to a resolution required for the control of the relative time difference between the timing at which the light reception section is to detect the light reception amount and the timing at which the light source is to project light.

Further, in the case where three or more types of delay amounts are utilized, also it is possible to utilize both of the first control example and the second control example described hereinabove in combination. As a particular example, in the case where first to third delay amounts whose delay adjustment resolutions are different from each other are utilized, the first delay amount and the second delay amount may be applied to control of the timing at which the light reception section is to detect the light reception amount while the third delay amount is applied to control of the timing at which the light source is to project light.

Further, as another example, the number of types of signals to which delays whose delay adjustment resolutions are different from each other are applied is not necessarily limited to two. In particular, three or more kinds of signals (for example, driving signals) may be made a target of the control relating to a delay described above. It is to be noted that, in this case, for example, the number of types of delay amounts to be used for control relating to a delay may be determined in response to the number of types of signals that are made a target of the control.

Further, the advantageous effects described in the present specification are explanatory and exemplary to the last and are not restrictive. In other words, the technology according to the present disclosure can play, together with or in places of the advantageous effects described above, other advantageous effects that are apparent to those skilled in the art from the description of the present specification.

It is to be noted that also such configurations as described below belong to the technical scope of the present disclosure.

(1)

A sensor chip, including:

a light reception section configured to receive light projected from a light source and reflected by an imaging target to detect, for each given detection period, a reception light amount of the reflected light within the given period;

a measurement section configured to measure a distance to the imaging object based on the reception light amount; and

a control section configured to apply at least one of a first delay amount or a second delay amount, whose resolutions relating to control are different from each other, to control of a first timing at which the light reception section is to detect the reception light amount thereby to control a relative time difference between the first timing and a second timing at which the light source is to project light with a resolution finer than the resolutions of the first delay amount and the second delay amount in response to the first delay amount and the second delay amount.

(2)

The sensor chip according to (1) above, in which

the control section controls the time difference by controlling the first delay amount to be applied to the control of the first timing in response to the second delay amount applied to the control of the second timing.

(3)

The sensor chip according to (1) above, in which

the control section controls the time difference by controlling the first delay amount and the second delay amount to be applied to the control of the first timing.

(4)

Electronic equipment, including:

a light source;

a light reception section configured to receive light projected from the light source and reflected by an imaging target to detect, for each given detection period, a reception light amount of the reflected light within the given period;

a measurement section configured to measure a distance to the imaging object based on the reception light amount; and

a control section configured to apply each of a first delay amount and a second delay amount, whose resolutions relating to control are different from each other, to control of one of a first timing at which the light reception section is to detect the reception light amount and a second timing at which the light source is to project light thereby to control a relative time difference between the first timing and the second timing with a resolution finer than the resolutions of the first delay amount and the second delay amount.

(5)

The electronic equipment according to (4) above, in which

the control section applies one of the first delay amount and the second delay amount to the control of the first timing and applies the other to the control of the second timing thereby to control the time difference.

(6)

The electronic equipment according to (4) above, in which

the control section applies both of the first delay amount and the second delay amount to one of the control of the first timing and the control of the second timing to control the time difference.

(7)

The electronic equipment according to any one of (4) to (6) above, in which

the control section controls the first delay amount and the second delay amount individually to control the time difference.

(8)

The electronic equipment according to any one of (4) to (7) above, further including:

a generation circuit configured to generate a first driving signal and a second driving signal, in which

the light reception section is driven based on the first driving signal, and

the light source is driven based on the second driving signal.

(9)

The electronic equipment according to (8) above, in which

the control section controls the time difference by delaying the generated first driving signal or second driving signal based on the first delay amount and the second delay amount.

(10)

The electronic equipment according to (8) above, in which

the generation circuit generates the first driving signal and the second driving signal in response to the first delay amount and the second delay amount, and

the driving of the light source and the light reception section is controlled based on the generated first driving signal and second driving signal thereby to control the time difference.

(11)

The electronic equipment according to any one of (4) to (10) above, in which

the control section includes

• • a first delay circuit configured to perform a delay for an input signal in accordance with the first delay amount, and
  • a second delay circuit configured to perform a delay for the input signal in accordance with the second delay amount, and

the first delay circuit and the second delay circuit are different in at least one of an additional capacitance of delay elements provided in each of the first delay circuit and the second delay circuit, a load resistance of the delay elements, a connection stage number of the delay elements or a size of a transistor applied to the delay elements.

(12)

The electronic equipment according to any one of (4) to (11) above, further including:

an error arithmetic operation section configured to calculate an error relating to measurement of a distance in response to a detection result of the reception light amount, in which

the control section controls at least one of the first delay amount or the second delay amount in response to a calculation result of the error.

(13)

An apparatus, including:

a light source;

a light reception section configured to receive light projected from the light source and reflected by an imaging target to detect, for each given detection period, a reception light amount of the reflected light within the given period;

a measurement section configured to measure a distance to the imaging object based on the reception light amount; and

a control section configured to apply each of a first delay amount and a second delay amount, whose resolutions relating to control are different from each other, to control of one of a first timing at which the light reception section is to detect the reception light amount and a second timing at which the light source is to project light thereby to control a relative time difference between the first timing and the second timing with a resolution finer than the resolutions of the first delay amount and the second delay amount.

(14)

An apparatus, including:

a control section configured to control operation of each of a light source and a light reception section configured to receive light projected from the light source and reflected by an imaging target to detect, for each given detection period, a reception light amount of the reflected light within the given period, in which

the control section applies each of a first delay amount and a second delay amount, whose resolutions relating to control are different from each other, to control of one of a first timing at which the light reception section is to detect the reception light amount and a second timing at which the light source is to project light thereby to control a relative time difference between the first timing and the second timing with a resolution finer than the resolutions of the first delay amount and the second delay amount, and

a distance to the imaging object is measured based on the reception light amount.

REFERENCE SIGNS LIST

• • 201: Distance image sensor
  • 202: Optical system
  • 203: Sensor chip
  • 204: Image processing circuit
  • 205: Monitor
  • 206: Memory
  • 211: Light source apparatus
  • 1010,1020: Phase adjustment circuit
  • 1011,1021: First variable delay circuit
  • 1013,1023: Second variable delay circuit
  • 1100: Distance image sensor
  • 1101: Sensor chip
  • 1111: Pixel array
  • 1113: Pixel driving circuit
  • 1115: Reading out circuit
  • 1120: PLL
  • 1130: Inputting and outputting section
  • 1140: Driving signal generation circuit
  • 1141: Pixel driving pulse generation circuit
  • 1143: Light source driving pulse generation circuit
  • 1150: Phase adjustment circuit
  • 1160: Control circuit
  • 1171: Light source
  • 1173: Light source driving circuit

Claims (14)

The invention claimed is:

1. A sensor chip, comprising:

a light sensor configured to receive light projected from a light source and reflected by an imaging target to detect, for each given detection period, a reception light amount of the reflected light within the given detection period; and

circuitry configured to:

measure a distance to the imaging target based on the reception light amount; and

apply a first delay amount and a second delay amount to a relative time difference between a first timing at which the sensor detects the reception light and a second timing at which the light source projects light, wherein the first delay amount and the second delay amount have different resolutions, such that the relative time difference has a resolution finer than the resolutions of the first delay amount and the second delay amount.

2. The sensor chip according toclaim 1, wherein

the circuitry is configured to control the relative time difference by controlling the first delay amount to be applied to the control of the first timing in response to the second delay amount applied to the control of the second timing.

3. The sensor chip according toclaim 1, wherein

the circuitry is configured to control the relative time difference by controlling the first delay amount and the second delay amount to be applied to the control of the first timing.

4. Electronic equipment, comprising:

a light source;

a light sensor configured to receive light projected from the light source and reflected by an imaging target to detect, for each given detection period, a reception light amount of the reflected light within the given detection period; and

circuitry configured to:

measure a distance to the imaging target based on the reception light amount; and

apply a first delay amount and a second delay amount to a relative time difference between a first timing at which the sensor detects the reception light and a second timing at which the light source projects light, wherein the first delay amount and the second delay amount have different resolutions, such that the relative time difference has a resolution finer than the resolutions of the first delay amount and the second delay amount.

5. The electronic equipment according toclaim 4, wherein

the circuitry is configured to apply one of the first delay amount and the second delay amount to the control of the first timing and to apply the other to the control of the second timing thereby to control the relative time difference.

6. The electronic equipment according toclaim 4, wherein

the circuitry is configured to apply both of the first delay amount and the second delay amount to one of the control of the first timing and the control of the second timing to control the relative time difference.

7. The electronic equipment according toclaim 4, wherein

the circuitry is configured to control the first delay amount and the second delay amount individually to control the relative time difference.

8. The electronic equipment according toclaim 4,

wherein the circuitry is further configured to generate a first driving signal and a second driving signal, wherein

the light sensor is driven based on the first driving signal, and

the light source is driven based on the second driving signal.

9. The electronic equipment according toclaim 8, wherein

the circuitry is configured to control the time difference by delaying the generated first driving signal or second driving signal based on the first delay amount and the second delay amount.

10. The electronic equipment according toclaim 8, wherein

the circuitry is configured to generate the first driving signal and the second driving signal in response to the first delay amount and the second delay amount, and

the driving of the light source and the light sensor is controlled based on the generated first driving signal and second driving signal thereby to control the relative time difference.

11. The electronic equipment according toclaim 4, wherein

the circuitry includes

a first delay circuit configured to perform a delay for an input signal in accordance with the first delay amount, and

a second delay circuit configured to perform a delay for the input signal in accordance with the second delay amount, and

the first delay circuit and the second delay circuit are different in at least one of an additional capacitance of delay elements provided in each of the first delay circuit and the second delay circuit, a load resistance of the delay elements, a connection stage number of the delay elements or a size of a transistor applied to the delay elements.

12. The electronic equipment according toclaim 4,

wherein the circuitry is further configured to calculate an error relating to measurement of a distance in response to a detection result of the reception light amount,

and to control at least one of the first delay amount or the second delay amount in response to a calculation result of the error.

13. An apparatus, comprising:

a light source;

a light sensor configured to receive light projected from the light source and reflected by an imaging target to detect, for each given detection period, a reception light amount of the reflected light within the given detection period; and

circuitry configured to:

measure a distance to the imaging target based on the reception light amount; and

apply each of a first delay amount and a second delay amount, whose resolutions relating to control are different from each other, to control of one of a first timing at which the light sensor is to detect the reception light amount and a second timing at which the light source is to project light thereby to control a relative time difference between the first timing and the second timing with a resolution finer than the resolutions of the first delay amount and the second delay amount.

14. An apparatus, comprising:

circuitry configured to control operation of each of a light source and a light sensor configured to receive light projected from the light source and reflected by an imaging target to detect, for each given detection period, a reception light amount of the reflected light within the given detection period, wherein

the circuitry applies each of a first delay amount and a second delay amount, whose resolutions relating to control are different from each other, to control of one of a first timing at which the light sensor is to detect the reception light amount and a second timing at which the light source is to project light thereby to control a relative time difference between the first timing and the second timing with a resolution finer than the resolutions of the first delay amount and the second delay amount, and

a distance to the imaging target is measured based on the reception light amount.

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